Posted by aionman on Aug 11, 2009 in
Ubuntu,
Zimbra
Ubuntu Backup and Restore
1: Backing-up
To do this, become root with
and go to the root of your filesystem (we use this in our example, but you can go anywhere you want your backup to end up, including remote or removable drives.)
Now, below is the full command I would use to make a backup of my system:
Code:
tar cvpzf backup.tgz --exclude=/proc --exclude=/lost+found --exclude=/backup.tgz --exclude=/mnt --exclude=/sys /
Since I always keep an update copy of my mail server, I’ll exclude that from the backup as well
Code:
tar cvpzf backup.tgz --exclude=/proc --exclude=/lost+found --exclude=/backup.tgz --exclude=/mnt --exclude=/sys --exlucde=/backup --exclude=/opt/zimbra /
Now, lets explain this a little bit.
The ‘tar’ part is, obviously, the program we’re going to use.
‘cvpfz’ are the options we give to tar, like ‘create archive’ (obviously),
‘preserve permissions’(to keep the same permissions on everything the same), and ‘gzip’ to keep the size down.
Next, the name the archive is going to get. backup.tgz in our example.
Next comes the root of the directory we want to backup. Since we want to backup everything; /
Now come the directories we want to exclude. We don’t want to backup everything since some dirs aren’t very useful to include. Also make sure you don’t include the file itself, or else you’ll get weird results.
You might also not want to include the /mnt folder if you have other partitions mounted there or you’ll end up backing those up too. Also make sure you don’t have anything mounted in /media (i.e. don’t have any cd’s or removable media mounted). Either that or exclude /media.
EDIT : kvidell suggests below we also exclude the /dev directory. I have other evidence that says it is very unwise to do so though.
Well, if the command agrees with you, hit enter (or return, whatever) and sit back&relax. This might take a while.
Afterwards you’ll have a file called backup.tgz in the root of your filessytem, which is probably pretty large. Now you can burn it to DVD or move it to another machine, whatever you like!
EDIT2:
At the end of the process you might get a message along the lines of ‘tar: Error exit delayed from previous errors’ or something, but in most cases you can just ignore that.
Alternatively, you can use Bzip2 to compress your backup. This means higher compression but lower speed. If compression is important to you, just substitute
the ‘z’ in the command with ‘j’, and give the backup the right extension.
That would make the command look like this:
Code:
tar cvpjf backup.tar.bz2 --exclude=/proc --exclude=/lost+found --exclude=/backup.tar.bz2 --exclude=/mnt --exclude=/sys /
2: Restoring
Warning: Please, for goodness sake, be careful here. If you don’t understand what you are doing here you might end up overwriting stuff that is important to you, so please take care!
Well, we’ll just continue with our example from the previous chapter; the file backup.tgz in the root of the partition.
Once again, make sure you are root and that you and the backup file are in the root of the filesystem.
One of the beautiful things of Linux is that This’ll work even on a running system; no need to screw around with boot-cd’s or anything. Of course, if you’ve rendered your system unbootable you might have no choice but to use a live-cd, but the results are the same. You can even remove every single file of a Linux system while it is running with one command. I’m not giving you that command though! 
Well, back on-topic.
This is the command that I would use:
Code:
tar xvpfz backup.tgz -C /
Or if you used bz2;
Code:
tar xvpfj backup.tar.bz2 -C /
WARNING: this will overwrite every single file on your partition with the one in the archive!
Just hit enter/return/your brother/whatever and watch the fireworks. Again, this might take a while. When it is done, you have a fully restored Ubuntu system! Just make sure that, before you do anything else, you re-create the directories you excluded:
Code:
mkdir proc
mkdir lost+found
mkdir mnt
mkdir sys
etc...
And when you reboot, everything should be the way it was when you made the backup!
2.1: GRUB restore
Now, if you want to move your system to a new harddisk or if you did something nasty to your GRUB (like, say, install Windows), You’ll also need to reinstall GRUB.
There are several very good howto’s on how to do that here on this forum, so i’m not going to reinvent the wheel. Instead, take a look here:
http://www.ubuntuforums.org/showthre…t=grub+restore
There are a couple of methods proposed. I personally recommend the second one, posted by remmelt, since that has always worked for me.
Re: HOWTO: Restore GRUB (if your MBR is messed up)
Isn’t it easier to do this:
1. Pop in the Live CD, boot from it until you reach the desktop.
2. Open a terminal window or switch to a tty.
3. Type “grub”
4. Type “root (hd0,6)”, or whatever your harddisk + boot partition numbers are (my /boot is at /dev/sda7, which translates to hd0,6 for grub).
5. Type “setup (hd0)”, ot whatever your harddisk nr is.
6. Quit grub by typing “quit”.
7. Reboot.
I may be missing your point though, if so, please forgive me 
Quote:
Originally Posted by vnbuddy2002
Restore GRUB quite simple in Ubuntu, instead going through all the “gain root access” and play with shell commands, you can use the Ubuntu installation CD to
restore it without going through all kinds of hassles.Here are the steps:
1. Boot your computer up with Ubunto CD
2. Go through all the process until you reech “[!!!] Disk Partition”
3. Select Manual Partition
4. Mount your appropriate linux partions
/
/boot
swap
…..
5. DO NOT FORMAT THEM.
6. Finish the manual partition
7. Say “Yes” when it asks you to save the changes
8. It will give you errors saying that “the system couldn’t install …..” after that
9. Ignore them, keep select “continue” until you get back to the Ubuntu installation menu
10. Jump to “Install Grub ….”
11. Once it is finished, just restart your computer
Good luck!.
Zimbra Emergency Repairs
Preparing to Back Up
Before we begin, make sure that you are logged in as a user that can perform the tasks outlined here.
It is always good practice to backup your copy of Zimbra in the event of unforeseen circumstances.
To prevent changes to any Zimbra databases during the backup processes you may wish to use:
>su zimbra
>zmcontrol stop
to terminate Zimbra.
If you get some kind of error, you may want to make sure that Zimbra has completly stopped by running:
>ps auxww | grep zimbra
and kill any left over processes such as the log.
Alternatively as root you could run the following command to kill all Zimbra user owned processes instantly (use wisely):
>ps auxww | awk '{print $1" "$2}' | grep zimbra | kill -9 `awk '{print $2}'`
Backing Up
Make sure that the copy location has enough space to support your backup copy (i.e. the /tmp folder probably isn’t the best location).
Since all of the components Zimbra needs are stored in the Zimbra folder itself, you can simply copy the folder to a safe location.
It may be possible to create a cron job to do these tasks automatically.
Copy Command: cp -Rp /opt/zimbra [location path]
Depending on your hardware and the amount of data contained in your Zimbra installation, this process can take a while.
Note: It is a very good idea to tag your installation with the version/build of zimbra that will be backed up (ie 3.0.0_GA_156) and the date of backup. You’ll need this later.
Restoring
Before restoring, you should make sure that all of the processes accociated with the damaged/failed Zimbra installation are terminated. Failure to terminate all of the processes could have dire consquences. See “Preparing to Backup” for additional info.
====Rename your “broken” Zimbra installation.’
You may be able to scavenge data, if needed. If you simply do not want the old data, you can skip this part.
>mv /opt/zimbra [new location i.e. /tmp/zimbra-old]
You may want to move it completly out of the /opt folder just to be safe.
Copy your backup Zimbra installation to the /opt folder and name it “zimbra”.
>cp -rp [location of backup] /opt
>mv /opt/[backup name] /opt/zimbra
Restore to Existing/Backup Zimbra Server
In the event of a failure, you can either restore your /opt/zimbra folder to a server that is not currently running Zimbra and download a dummy copy of Zimbra and run an upgrade in order to clean everything up and make it run correctly again (see next section), or you may restore the backup to an existing Zimbra server. This will only work if the existing server is running the EXACT SAME VERSION of Zimbra as the backup you want to restore. Also, this has been tested and seems to work well with CE 4.5.8, but did not work with 4.5.7. This may be, for example, a backup email server that you want to always keep current with last night’s backup, so it can replace the production server on short notice in the event of a disaster.
Simply set up your backup server identical to your production server (preferably the same OS, but necessarily the exact same version of Zimbra). Any modifications you made or packages you added for your production server with regards to extra anti-spam protection, etc., should also be added to this server. Shut down Zimbra on the backup server. Copy /opt/zimbra from your backup to the backup server.
chown -R zimbra:zimbra /opt/zimbra
/opt/zimbra/libexec/zmfixperms
Start Zimbra. Everything should work. The advantage to this method is that you can retain all your customizations (anti-spam modifications, for example) that would otherwise have been lost in the “upgrade” method. Also, this allows you to use a script to keep a backup server current without having to reinstall Zimbra after each time the backup server is made current, or before putting the backup server into production in the event of a failure.
Downloading a Dummy Copy of Zimbra
Now, we need to know what build/version of zimbra you were running. If you followed the backup instructions above, then the backup folder should be tagged with the version/build you have backed up.
You need to download the full install of the Zimbra version you were running. You may find all Zimbra releases at: Sourceforge.
If you don’t know your version number, you can find it by:
Method 1 - view install_history file.
cat /opt/zimbra/.install_history
Method 2 - dont think this will work unless you did a bunch of chroots.
zmcontrol -v
Both of the above listed methods were from this forum post
Installing the Dummy Copy of Zimbra
Once you have downloaded the tar file, you will need to uncompress it by:
>tar -xvzf [name of file].tgz
This will create a folder in the directory named “zcs”, cd to it and run the install script:
>cd zcs
>./install.sh
WARNING: Do not run the script with the -u option. You will remove all of your backup data & you must run the script as root, NOT ZIMBRA.
The script will remove the existing packages, and install them again. The script will attempt to stop Zimbra Services and “UPGRADE FAILED – exiting”. This is okay, simply rerun the script, and it will install normally.
If you experence error 389, -1, connection refused errors, please search the Forums. These errors are covered extensivly.
Resetting Permissions
If you are up and running now, you may have one more hurdle to overcome: permissions.
You may need to reset the permissions on the message store by running the following:
>/opt/zimbra/libexec/zmfixperms
This is potentially a dangerous suggestion, but if you have trouble getting tomcat to start even after you run zmfixperms, try running (worked for ZCS 4.5.7 CE)
chown -R zimbra:zimbra /opt/zimbra
Of course, you must run
/opt/zimbra/libexec/zmfixperms
again after that. It appears that zmfixperms is supposed to chown zimbra:zimbra on something, but it misses it. This way, you chown EVERYTHING zimbra:zimbra, and zmfixperms puts back things that need to be owned as root, postfix, etc.
Disaster Recovery
In the unfortunate event of losing your complete server or installation, the following will get you up and running.
This has been tested successfully on v5.0.5
- The machine you are recovering to must have the same hostname as the original machine.
- Once you have your OS and all pre-requisites installed. Download and install Zimbra as normal.
- Once Zimbra is installed, stop all Zimbra services and move/rename the /opt/zimbra folder:
sudo -u zimbra /opt/zimbra/bin/zmcontrol shutdown
mv /opt/zimbra /tmp/zimbra-old
- Uncompress the most recent backup file to the /opt/zimbra folder
mkdir /opt/zimbra
tar zxvf [backup file] -C /opt/zimbra
or if you prefer…
tar zxvf [backup file] -C /tmp/zimbra-backup
cp -Rp /tmp/zimbra-backup /opt/zimbra
- Fix the Zimbra permissions
chown -R zimbra:zimbra /opt/zimbra
/opt/zimbra/libexec/zmfixperms
- Restart all Zimbra services
sudo -u zimbra /opt/zimbra/bin/zmcontrol startup
zmcontrol startup
You should now be able to access Zimbra as normal.
Posted by aionman on Aug 5, 2009 in
Ubuntu You can repair a corrupted filesystem with the program “fsck”.The system utility fsck (for “file system check” or “file system consistency check”) is a tool for checking the consistency of a file system in Unix and Unix-like operating systems such as Linux.
Note:- File systems must be unmounted, you cannot repair them while they are running.So fsck must ALWAYS be run on an UNmounted filesystem. Running fsck on a mounted filesystem can do SEVERE damage.
A quick fsck options overview:
Many options for fsck exist, but the most important are:
-f which performs a FAST check
-p which fixes minor problems without user interaction
-y which gives permission to correct every problem found
-n which indicates to only search (and not correct) problems
The most simple variant to run fsck is to force fsck on restart, and then restart your system:
sudo touch /forcefsck
The other option is to swich the system to runlevel 1 (logs-out any userRunning fsck on a mounted filesystem can do SEVERE damage), unmount all partitions. run fsck & repair, remount all drives, increase the runlevel to 3 and continue.
1) Take system down to runlevel one (make sure you run all command as root user):
# init 1
2)Unmount file system, for example if it is /home (/dev/sda3) file system then type command:
# umount /home
OR
# umount /dev/sda3
3) Now run fsck on the partition:
# fsck /dev/sda3
However be sure to specify the file system type using -t option. Recenly one of our sys admin run the command on ext3 file system w/o specifying file system. Result was more corruption as fsck by default assumes ext2 file system.
# fsck -t ext3 /dev/sda3
OR
# fsck.ext3 /dev/sda3
Tip if you don’t know your file system type then typing mount command will display file system type.
fsck will check the file system and ask which problems should be fixed or corrected. If you don’t wanna type y every time then you can use pass -y option to fsck.
# fsck -y /dev/sda3
Please not if any files are recovered then they are placed in /home/lost+found directory by fsck command.
4) Once fsck finished, remount the file system:
# mount /home
5) Go to multiuser mode
# init 3
Read man page of fsck for more information. Make sure you replace /dev/sda3 with your actual device name.
Posted by aionman on Aug 4, 2009 in
Linux,
Ubuntu This guide shows how to remove a failed hard drive from a Linux RAID1 array (software RAID), and how to add a new hard disk to the RAID1 array without losing data.
I do not issue any guarantee that this will work for you!
1 Preliminary Note
In this example I have two hard drives, /dev/sda and /dev/sdb, with the partitions /dev/sda1 and /dev/sda2 as well as /dev/sdb1 and /dev/sdb2.
/dev/sda1 and /dev/sdb1 make up the RAID1 array /dev/md0.
/dev/sda2 and /dev/sdb2 make up the RAID1 array /dev/md1.
/dev/sda1 + /dev/sdb1 = /dev/md0
/dev/sda2 + /dev/sdb2 = /dev/md1
/dev/sdb has failed, and we want to replace it.
2 How Do I Tell If A Hard Disk Has Failed?
If a disk has failed, you will probably find a lot of error messages in the log files, e.g. /var/log/messages or /var/log/syslog.
You can also run
cat /proc/mdstat
and instead of the string [UU] you will see [U_] if you have a degraded RAID1 array.
3 Removing The Failed Disk
To remove /dev/sdb, we will mark /dev/sdb1 and /dev/sdb2 as failed and remove them from their respective RAID arrays (/dev/md0 and /dev/md1).
First we mark /dev/sdb1 as failed:
mdadm –manage /dev/md0 –fail /dev/sdb1
The output of
cat /proc/mdstat
should look like this:
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[2](F)
24418688 blocks [2/1] [U_]
md1 : active raid1 sda2[0] sdb2[1]
24418688 blocks [2/2] [UU]
unused devices: <none>
Then we remove /dev/sdb1 from /dev/md0:
mdadm –manage /dev/md0 –remove /dev/sdb1
The output should be like this:
server1:~# mdadm –manage /dev/md0 –remove /dev/sdb1
mdadm: hot removed /dev/sdb1
And
cat /proc/mdstat
should show this:
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0]
24418688 blocks [2/1] [U_]
md1 : active raid1 sda2[0] sdb2[1]
24418688 blocks [2/2] [UU]
unused devices: <none>
Now we do the same steps again for /dev/sdb2 (which is part of /dev/md1):
mdadm –manage /dev/md1 –fail /dev/sdb2
cat /proc/mdstat
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0]
24418688 blocks [2/1] [U_]
md1 : active raid1 sda2[0] sdb2[2](F)
24418688 blocks [2/1] [U_]
unused devices: <none>
mdadm –manage /dev/md1 –remove /dev/sdb2
server1:~# mdadm –manage /dev/md1 –remove /dev/sdb2
mdadm: hot removed /dev/sdb2
cat /proc/mdstat
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0]
24418688 blocks [2/1] [U_]
md1 : active raid1 sda2[0]
24418688 blocks [2/1] [U_]
unused devices: <none>
Then power down the system:
shutdown -h now
and replace the old /dev/sdb hard drive with a new one (it must have at least the same size as the old one – if it’s only a few MB smaller than the old one then rebuilding the arrays will fail).
4 Adding The New Hard Disk
After you have changed the hard disk /dev/sdb, boot the system.
The first thing we must do now is to create the exact same partitioning as on /dev/sda. We can do this with one simple command:
sfdisk -d /dev/sda | sfdisk /dev/sdb
You can run
fdisk -l
to check if both hard drives have the same partitioning now.
Next we add /dev/sdb1 to /dev/md0 and /dev/sdb2 to /dev/md1:
mdadm –manage /dev/md0 –add /dev/sdb1
server1:~# mdadm –manage /dev/md0 –add /dev/sdb1
mdadm: re-added /dev/sdb1
mdadm –manage /dev/md1 –add /dev/sdb2
server1:~# mdadm –manage /dev/md1 –add /dev/sdb2
mdadm: re-added /dev/sdb2
Now both arays (/dev/md0 and /dev/md1) will be synchronized. Run
cat /proc/mdstat
to see when it’s finished.
During the synchronization the output will look like this:
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[1]
24418688 blocks [2/1] [U_]
[=>...................] recovery = 9.9% (2423168/24418688) finish=2.8min speed=127535K/sec
md1 : active raid1 sda2[0] sdb2[1]
24418688 blocks [2/1] [U_]
[=>...................] recovery = 6.4% (1572096/24418688) finish=1.9min speed=196512K/sec
unused devices: <none>
When the synchronization is finished, the output will look like this:
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[1]
24418688 blocks [2/2] [UU]
md1 : active raid1 sda2[0] sdb2[1]
24418688 blocks [2/2] [UU]
unused devices: <none>
That’s it, you have successfully replaced /dev/sdb!
Tags: RAID, Rebuild RAID
Posted by aionman on Jul 30, 2009 in
Linux,
Ubuntu sudo aptitude install nis dhcp3-server tftpd (may fail start the service because /etc/dhcp3/dhcpd.conf is not configured)
sudo ifconfig eth0:1 192.168.0.1 (when system only has 1 nic port)
# import gpg key
wget -q http://drbl.sourceforge.net/GPG-KEY-DRBL -O- | sudo apt-key add -
# add following line into source list
# then aptitude update and install drbl
deb http://drbl.sourceforge.net/drbl-core drbl stable testing unstable
# For setting up system environment, here has lots of setting, and choose which IP to be the PXE interface should be the most important portion.
sudo /opt/drbl/sbin/drblsrv -i
sudo /opt/drbl/sbin/drblpush -i
———————————–
# start to use clonezilla
sudo /opt/drbl/sbin/dcs
# clone the client image
All –> clonezilla-start –> Beginner –> save-disk
# restore the local image to the client
All –> clonezilla-start –> Beginner –> restore-disk
Tags: Clone, clone server
Posted by aionman on Jul 27, 2009 in
Ubuntu,
Zimbra Zimbra reponse with 5-10s before SMTP banner
220 mail.example.com ESMTP Postix
Need to do a trace at the server
tcpdump -s 1500 -w /tmp/server_trace.pcap
Looking at a wireshark trace, i see the server sending out “MDNS” packets which was installed along with ubuntu-desktop.
sudo update-rc.d -f avahi-daemon remove
/etc/init.d/avahi-daemon stop
Posted by aionman on Jul 24, 2009 in
Ubuntu,
Zimbra Ubuntu 8.04 LTS Server (Hardy Heron) Install Guide
The following guide is for installing ZCS on Ubuntu Server 8.04 LTS, and is a revision of my previous Ubuntu Server 6.06 installation guide here. Please verify which version you are using and follow the appropriate guide, as there are material differences between the two. I have tested this guide with the 32-bit version of Ubuntu only; others will need to verify if any tweaks are necessary for a 64-bit installation.
This installation is for a split-DNS setup, where the server resides on a DMZ and so needs to resolve to its own internal (DMZ subnet) IP address rather than the public IP address that is published to the world. This is a setting where a firewall/router supplies the translation from the public IP to the DMZ IP (DNAT–Destination Network Address Translation) so that translation is not known to the server itself. This configuration is desirable for security, but it makes bits of the Zimbra configuration more complex than they might otherwise be.
For simplicity’s sake I’m referring to Zimbra’s DMZ address as the “private ip address” from here on. By that I mean that the Zimbra box has only one IP address, it’s on the DMZ, and can be seen by my LAN but not the public. When I say “public IP address” I’m not talking about another address on the Zimbra box, but rather the address that gets DNATed to my box and which is resolved in the world.
Installing Ubuntu 8.04 LTS
Obtain your installation binary from Ubuntu at http://www.ubuntu.com/getubuntu/download. Be sure you download the LTS (Longterm Support) Server Edition, NOT the Desktop Edition. Burn the iso file to a CD and boot it in your server. There is an excellent, highly-detailed installation guide for this version at http://www.howtoforge.com/perfect-server-ubuntu8.04-lts. I highly recommend this guide, particularly if you are new to Linux or Ubuntu specifically. The following points need to be kept in mind as you install:
1) The installation (and the guide) want to configure your LAN via DHCP. Cancel it before it gets that far, and manually configure it with a static IP address, netmask, and gateway. Don’t put in a public DNS for your nameserver configuration; instead put in the same IP address that you just gave the machine for its own static IP (this won’t let you resolve names on the internet until we do some more configuration below, but it saves headaches later).
2) When the installation asks for a hostname, give it only a one-word hostname (e.g. “mail” or “myserver”) NOT the fully-qualified domain name (mail.mydomain.com). In the next screen where it asks for the domain name, give the “mydomain.com” part without the hostname.
3) Hard disk configuration is easy if you are using a single drive, but for a server, that’s not the most secure way to do things. Ideally you should have either a RAID-1 or a RAID 1+0 configuration for your disks to provide redundancy. Most ideally that would be hardware-RAID, but configuring it in Ubuntu is a challenge. Software RAID (native to Linux) on the other hand, is easy IF you set it up AT THE TIME YOU ARE PARTITIONING YOUR DISKS. See this howto http://www.howtoforge.com/how-to-install-ubuntu8.04-with-software-raid1 for setup instructions if you want to use software RAID. As to partitioning your drives, you can find a variety of opinions. I just make a small partition for swap (1.5-2x RAM) and the rest for the whole system. Others will recommend separate partitions for mailstore, system, etc. Use your own judgement here.
4) Once the base system has been installed, the installer will ask you for a username, and then a password for that user. This needs to be a non-root user, and unlike previous Ubuntu versions, the user “admin” is no longer accepted. Whatever you choose, that username and password will be what you use to log in at the command line later, and the same password will be the password for sudo commands. Be sure you remember what you put in here!
5) At the “Software Selection” screen, select the DNS Server and OpenSSH Server options for installation, but nothing else. This will allow remote administration (SSH), and will install bind9 which you will need for split DNS.
6) Run the following command to make sure you have all the necessary packages: sudo apt-get install bind9 dnsutils file libgmp3c2 libexpat1 libstdc++5 libltdl3 libperl5.8 perl curl libpcre3 libc6
With these items, your installation will complete and the system will reboot.
This guide shows how to install the Zimbra Collaboration Suite (ZCS) on Ubuntu 6.10 (Edgy Eft) and 6.06 (Dapper Drake) server systems. Zimbra is a full-featured, open source collaboration suite – email, group calendaring, contacts, and web document management and authoring. It has a feature-rich AJAX web interface and is compatible with clients such as Microsoft Outlook, Apple Mail, and Novell Evolution so that mail, contacts, and calendar items can be synchronised from these to the ZCS server. It can also be synchronized to many mobile devices. ZCS makes use of many existing open source projects such as Postfix, MySQL, and OpenLDAP.
I do not issue any guarantee that this will work for you!
1.1 Enable The root Account
To enable the root account, run
and specify a password for root.
Afterwards, become root by running
All following commands in this tutorial are executed as root (unless something else is written)!
1.2 Install The SSH Daemon
Just run
apt-get install ssh openssh-server
to install the SSH daemon.
1.3 Apply A Static IP Address And Hostname
Edit /etc/network/interfaces and adjust it to your needs (in this example setup I will use the IP address 192.168.0.110):
vi /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 inet static
address 192.168.0.110
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1
|
Then restart your network:
/etc/init.d/networking restart
Then edit /etc/hosts. Make it look like this:
127.0.0.1 localhost.localdomain localhost
192.168.0.110 mail.example.com mail
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
|
Now run
echo mail.example.com > /etc/hostname
and reboot the system:
Afterwards, run
Both should show mail.example.com.
From now on you can use an SSH client such as PuTTY and connect from your workstation to your Ubuntu server and follow the remaining steps from this tutorial.
DNS
Proper DNS configuration is PARAMOUNT! If you don’t have your DNS working properly, don’t even bother trying to install Zimbra, because trying to fix DNS after the fact may result in an install that can do everything except send mail–even from a Zimbra user to himself! So I’ll say it again:
If you can’t resolve your mailserver’s own private IP address (NOT the public IP) using nslookup, fix it BEFORE you install Zimbra!
If your installation above was successful, when you sign on at the command line you’ll be able to ping public IP addresses if you know them, but you may not be able to resolve any names to ping them.
Now you have to configure the following files, which are in the directory /etc/bind (for brevity I’ve deleted the generic comment lines included by the distro). Note that the query-source address and forwarders lines are already there, they just need to be uncommented, and in the case of the forwarders, the ip addresses of your ISP’s DNS servers need to be added. Note also that the syntax needs to be EXACTLY as shown below–leave out one semicolon or bracket and the whole thing blows up:
/etc/bind/named.conf.options
options {
directory "/var/cache/bind";
query-source address * port 53;
forwarders {
xxx.xxx.xxx.xxx; xxx.xxx.xxx.xxx;
};
auth-nxdomain no; # conform to RFC1035
};
the ip addresses on this file are public ip addresses of the DNS you use in the outside world. The line “query-source address * port 53″ is to allow your machine to hit the DNS if oddball DNS ports are blocked. You can leave it commented if you don’t need it.
Check /etc/resolv.conf and make sure it looks like this:
nameserver xxx.xxx.xxx.xxx
The IP address here should be the Zimbra box’s private ip address.
Once you’ve fixed these two files and restarted bind
/etc/init.d/bind9 restart
you should be able to resolve names in the outside world. Try something like “ping google.com” and if you get an answer, you’re on the way.
Now it’s time to get the internal zone working. Append the following lines to /etc/bind/named.conf.local
zone "mydomain.com" {
type master;
file "/etc/bind/db.mydomain.com";
};
Note that you need to type the full pathname to your db.* file. Also, be sure you don’t miss a semicolon “;” in any of these lines that have them because a missing semicolon breaks the file.
Now create your file /etc/bind/db.mydomain.com
;
; BIND data file for mydomain.com
;
$TTL 604800
@ IN SOA mail.mydomain.com. admin.mydomain.com. (
070725 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
@ IN NS mail
IN MX 10 mail
IN A xxx.xxx.xxx.xxx
mail IN A xxx.xxx.xxx.xxx
The ip address here is again your Zimbra internal ip address; the string “admin.mydomain.com” is replaced with the email address you are using for administration, only with a “.” instead of the “@” in the address. Be careful to increment the serial number one higher every time you modify this file or the changes won’t stick. Many users use the date they edit the file for the serial number, but as long as you start low and only get higher it really doesn’t matter.
Now you may need to reboot the machine (restarting bind9 alone doesn’t always work) and try to resolve your mail server.
nslookup mydomain.com
If it returns your public IP address, your internal DNS is not working. If things are configured correctly it’ll return the internal address.
Hosts Table
Before you get to the install you also need to modify your /etc/hosts file:
127.0.0.1 localhost.localdomain localhost
10.3.2.244 mail.tractor-equip.net mail
ONLY IF this is working, it’s now time to update your packages:
sudo bash (this will ask for your password, enter your administrator's pw, then you'll be at a root prompt)
apt-get upgrade
apt-get update
Now you’re ready to install Zimbra.
Installing ZCS
Several discussion groups have listed the dependencies not installed by the standard Linux install, but the easy thing to do is try to run the install and let Zimbra give you a list of what’s missing. Download the appropriate package for your Ubuntu installation (32 or 64 bit Ubuntu 8.04 LTS), copy it into your choice directory (I prefer /temp because /tmp is volatile and clears out every reboot), change to that directory, and type
tar -xzf zc*
and it’ll create a whole directory /temp/zcs with lots of files inside it. Then:
cd /temp/zcs
./install.sh
It’s not going to work the first time, but it’ll give you a list of missing dependencies. Write down all the package names it says are missing. Your list may be slightly different than mine, but whatever it is, load them. Just separate each package name with a space like this:
apt-get install libpcre3 libgmp3c2 libstdc++5
Now re-run your Zimbra install and accept all the defaults except:
When it asks you for your domain, it’s going to have your fully-qualified domain name (hostname.mydomain.com) rather than just the domain, and probably complain about not having an MX record. Change the hostname to just mydomain.com and it’ll find the names through nslookup, and it’ll be happy. The rest of the install should proceed without errors, except that toward the end it’s going to ask you to “Adress unconfigured items” but, if you’re doing this from the console and not from an SSH connection with a buffer, the actual item that’s unconfigured is off the screen and invisible. It’s the admin password, which is in menu item 3.
Finally, when the install is done and it has given you the last “press Enter to finish” you are almost done. I recommend at this point that you convert your webmail to use https rather than http. This is a security question, but it is also discretionary. If you choose to do this, then at the command prompt, type:
su - zimbra
zmtlsctl https
Now reboot the system, and when it comes back up,give it a couple minutes to start the rest of the Zimbra processes. If your installation is successful, you can go to https://xxx.xxx.xxx.xxx:7071 (your internal ip address again) to get the administrative console, or
https://xxx.xxx.xxx.xxx to log in as a user.
Congratulations–one shiny new Zimbra installation on Ubuntu!
Posted by aionman on Jul 15, 2009 in
Ubuntu Setting up software RAID in Ubuntu Server
April 24th, 2007 Posted by Derrick Webber
Updated Mar 13 2009 to reflect improvements in Ubuntu 8.04 and later.
Linux has excellent software-based RAID built into the kernel. Unfortunately information on configuring and maintaining it is sparse. Back in 2003, O’Reilly published Managing RAID on Linux and that book is still mostly up to date, but finding clear instructions on the web for setting up RAID has become a chore.
Here is how to install Ubuntu Server with software RAID 1 (disk mirroring). This guide has been tested on Ubuntu Server 8.04 LTS (Hardy Heron). I strongly recommend using Ubuntu Hardy or later if you want to boot from RAID1.
Software RAID vs. hardware RAID
Some system administrators still sneer at the idea of software RAID. Years ago CPUs didn’t have the speed to manage both a busy server and RAID activities. That’s not true any more, especially when all you want to do is mirror a drive with RAID1. Linux software RAID is ideal for mirroring, and due to kernel disk caching and buffering it can actually be faster than RAID1 on lower end RAID hardware. However, for larger requirements like RAID 5, the CPU can still get bogged down with software RAID.
Software RAID is inexpensive to implement: no need for expensive controllers or identical drives. Software RAID works with ordinary EIDE, Serial ATA and SCSI drives and controllers. You can mix together whatever drive types and sizes you have on hand. When all you need are mirrored drives, software RAID is an especially good choice.
However, there are reasons you might prefer hardware RAID over software RAID:
- Hardware RAID is simpler to setup and manage.
- Depending on the server BIOS, a system using Linux software RAID probably won’t be able to boot automatically when the first disk of a mirror is first replaced with a new blank drive (It can still be booted manually though).
- Linux will only boot when the “/boot” and “/” partitions are on RAID1. It cannot boot when those partitions are on RAID5. Other partitions, however, can be RAID5.
- With software RAID, after replacing a failed drive the administrator must login and enter commands to add the new drive to the array and re-sync the contents. Good hardware RAID controllers re-sync automatically as soon as they see a new drive, without operator intervention.
Notice I said “good hardware controllers”. Low-end controllers like those integrated with consumer-grade motherboards that require software drivers are not suitable for server use. Cheap motherboard RAID (often called “fake RAID”) is designed for gamers who want RAID 0 to boost disk read times, not for reliability. Server-grade hardware RAID requires controllers from Adaptec, 3ware or another reputable manufacturer.
A simple RAID1 example
For this example we’ll construct a simple RAID1 mirror using a server that has two 4 GB serial ATA drives. Such a configuration will keep running if either drive fails, but (obviously) not if both fail.
EIDE or SCSI drives can be used with Linux RAID, but right now serial ATA provides the best combination of low cost, performance and flexibility.
For this example, partitioning will be done as simply as possible:
| Drive |
Partition |
Type |
Mounted on |
Size |
| Drive0 |
/dev/sda1 |
Primary |
/ |
4.1 GB |
| /dev/sda2 |
Primary |
(swap area) |
(remainder of disk) |
| Drive1 |
/dev/sdb1 |
Primary |
/ |
4.1 GB |
| /dev/sdb2 |
Primary |
(swap area) |
(remainder of disk) |
In Linux software RAID each mount point is usually configured as a separate RAID device. It’s possible for entire drives to be RAID members rather than each partition (e.g. combine /dev/sda and /dev/sdb) but the resulting device will not be bootable.
In this example partitions sda1 and sdb1 will be made members of a RAID1 device named /dev/md0. Partitions sda2 and sdb2 will be members of a RAID1 device named /dev/md1.
| RAID device |
Type |
Mounted on |
Size |
Members |
| /dev/md0 |
RAID1
mirror |
/ |
4.1 GB |
/dev/sda1 |
| /dev/sdb1 |
| /dev/md1 |
RAID1
mirror |
(swap) |
(remainder of disk) |
/dev/sda2 |
| /dev/sdb2 |
On a real world server it’s a good idea to have at least /var and /home on their own partitions, but the above scheme is good enough for this example. We are also purposely avoiding complications like logical volume management (LVM), just to keep things simple.
In Linux RAID, corresponding partitions on each drive in a RAID device should be the same size. If they aren’t, software RAID will still work but each RAID device will only be as large as the smallest member partition (e.g. if you add a 10GB partition and a 20GB partition into a RAID1 array, the resulting array will only have 10GB of usable space).
Installing Ubuntu server with RAID1
To install a fresh Ubuntu System with RAID, boot from the CD-ROM as usual. Follow the prompts until you get at the “Partition Disks” dialog.
- From the “Partitions Disks” dialog box, select “Manually edit the partition table”.
- Select the first disk (”sda”)
- Say yes to “Create a new empty partition table on this device?”
- Use the dialog boxes to create a new primary partition large enough to hold the root filesystem but leave space for a swap partition (4.1 GB in this example).
- For “How to use this partition” select “physical volume for RAID“, not the default “Ext3 journaling file system”
- Make the partition bootable (Bootable flag “on”)
- Use the dialogs to create one other primary partition taking up the remaining disk space (197.4 MB in this example). Later this will be used for swap.
- For “How to use this partition” select “physical volume for RAID“, not the default “Ext3 journaling file system” and not “swap area”
- Repeat the above steps to create identical partitions on the second drive. Remember to mark partition one on both drives as “bootable”. The final result should look similar to the following:
(click for full size)
- Once the partitions are configured, at the top of the “Partition Disks” main dialog select “Configure Software RAID”
- When asked “Write the changes to the storage devices and configure RAID” select “Yes”.
- For “Multidisk configuration actions” select “Create MD device”
- For “Multidisk device type” select “RAID1″
- For “Number of active devices for the RAID1 array” enter “2″
- For Number of spare devices for the RAID1 array” enter “0″ (zero)
- When asked to select “Active devices for the RAID1 multidisk device” select both /dev/sda1 and /dev/sdb1
- From the next dialog select “create MD device”
- Repeat the above steps to create an MD device that contains /dev/sda2 and /dev/sdb2
- Finally, from the dialog “Multidisk configuration actions” select “Finish”
Next configure RAID #0 (md0) to be mounted as the “/” filesystem and RAID device #1 (md1) to be mounted as swap:
- From the “Partition Disks” dialog, move the cursor bar under “RAID device #0″ and select “#1 4.1 GB”
- Configure the device as an Ext3 filesystem mounted on /, as shown:
(click image for full size)
- From the Partition Disks dialog under “RAID device #1″ select “#1 197.3 MB”
- Configure the device as “swap area”, as shown:
(click image for full size)
- The final partitioning screen should resemble the following:
(click image for full size
- Select “Finish partitioning and write changes to disk”.The RAID1 mirrors are created and made active, the filesystem is formatted and installation of Ubuntu proceeds as usual.
- Allow the installation to complete then reboot when requested.
Booting with a failed drive
The GRUB bootloader has always made it tricky to boot from a RAID array when one of the drives has failed. Fortunately, the Ubuntu team improved the situation in Ubuntu 8.10 Intrepid Ibex and backported the changes to Ubuntu Server 8.04 Hardy Heron (See Bug 290885 for the whole saga).
Now administrators can choose how the server will behave when a drive in a RAID array has failed:
- Wait at a boot prompt for manual intervention (the default), or
- Automatically boot from the other drive
Most administrators will want option 2. After all, the purpose of RAID is to increase server availability. However, with some hardware failures automatically booting could wipe out data on the remaining drive. If you have good backup and recovery procedures, that risk is probably acceptable, but it is your decision as administrator.
To make Ubuntu Server automatically boot when one drive in a RAID array has failed do the following:
- From a running server, do a package update to make sure you have the latest kernel and boot loader (e.g. sudo apt-get update; apt-get upgrade).
- Reboot the server to ensure any new kernel and bootloader packages are in place.
- From the command line run “sudo grub-install /dev/md0″ to ensure GRUB is installed on all members of the boot RAID device.
- From the command line run “sudo dpkg-reconfigure mdadm”
- When asked “Should mdadm run monthly redundancy checks of the RAID arrays?”, select either Yes or No (read the warning about possible performance impact and decide. “Yes” is the safer choice)
- When asked “Do you want to start the md monitoring daemon?” select Yes.
- Enter a valid email address to send warning messages to.
- When asked “Do you want to boot your system if your RAID becomes degraded?” selected Yes.
Now when the system boots and either of the drives has failed, the system will seem to hang at the “Loading, please wait…” stage for approximately five minutes, then proceed to boot normally.
Some friendly advice
RAID systems that boot and continue to function with failed members are great for continuity, but we often see administrators either not notice that drives have failed, or wait to long to replace them.
Suddenly the last drive also dies and they face a long downtime while the system is rebuilt or restored. It may seem obvious, but when dealing with RAID:
- Make sure your system properly alerts you when a drive fails. Don’t just rely on the MD monitoring daemon to send email alerts: also run smartmontools to monitor physical health and setup a script in your server monitor (e.g. monit or Nagios), run a script from cron that parses /proc/mdstat, or whatever method works best in your environment.
- Don’t wait to repair or replace the failed drive. When a drive fails, act immediately. Drives had a eerietendancy to fail at nearly the same time, especially when they are identical models and purchased at the same time.
Why RAID swap?
You might be wondering why we put swap on a RAID device, causing system swap activity to suffer the additional overhead of RAID.
Though Linux is capable of handling multiple independent swap partitions on multiple drives, if a drive containing an active swap partition dies it may take the system down with it. That defeats the point of having RAID in the first place, so to avoid that possibility we put the swap in RAID.
This creates more overhead, but swap is only meant as temporary substitute memory during rare moments of memory exhaustion. If the system is regularly using swap, performance is already being severely impacted and it’s time to add more physical memory.
Care and feeding
Having two drives configured in a RAID1 mirror allows the server to continue to function when either drive fails. When a drive fails completely, the kernel RAID driver automatically removes it from the array.
However, a drive may start having seek errors without failing completely. In that situation the RAID driver may not remove it from service and performance will degrade. Luckily you can manually remove a failing drive using the “mdadm” command. For example, to manually mark both of the RAID devices on drive sda as failed:
mdadm /dev/md0 –fail /dev/sda1
mdadm /dev/md1 –fail /dev/sda2
The above removes both RAID devices on drive sda from service, leaving only the partitions on drive sdb active.
Removing a failed drive
When Ubuntu sees that RAID has been configured, it automatically runs the mdadm command in “monitor mode” to watch each device and send email to root when a problem is noticed. You can also manually inspect RAID status using commands like the following:
cat /proc/mdstat
mdadm –query –detail /dev/md0
mdadm –query –detail /dev/md1
As mentioned above, it’s wise to use the smartmontools package to monitor each drive’s internal failure stats. However, as noted in a recent analysis by Google (PDF link), drives are perfectly capable to dying without any warning showing in their SMART indicators.
To replace a drive that has been marked as failed (either automatically or by using “mdadm –fail”), first remove all partitions on that drive from the array. For example to remove all partitions from drive sda:
mdadm /dev/md0 –remove /dev/sda1
mdadm /dev/md1 –remove /dev/sda2
Once removed it is safe to power down the server and replace the failed drive.
Boot problems
If it was the first drive that failed, after replacing it with a new unformatted drive the system may no longer boot: some BIOSs only attempt to boot from the lowest numbered hard drive (e.g. sda or hda) and if it is blank the system will hang. In that case you’ll need a rescue CD capable of running a GRUB boot prompt so you can manually boot from the second physical drive.
There are many free Linux-based rescue CDs available (e.g. SystemRescueCD) but for quick access to GRUB try the Super Grub Disk. This small download can be written to bootable floppy or CDROM and give quick access to system boot tools, especially the GRUB command line.
Whatever rescue tool you use, use it to boot to a GRUB command prompt and force the system to boot from the second installed hard drive using commands similar to the following:
root (hd1,0)
kernel /boot/vmlinuz-whatever root=/dev/md0 ro
initrd /boot/initrd.img-whatever
boot
To find the correct file names for the “kernel” and “initrd” parameters, GRUB has bash-style command-line completion… type just enough of the path then press TAB to auto-complete or see a list of available choices.
Preparing the new drive
Once system as been rebooted with the new unformatted replacement drive in place, some manual intervention is required to partition the drive and add it to the RAID array.
The new drive must have an identical (or nearly identical) partition table to the other. You can use fdisk to manually create a partition table on the new drive identical to the table of the other, or if both drives are identical you can use the “sfdisk” command to duplicate the partition. For example, to copy the partition table from the second drive “sdb” onto the first drive “sda”, the sfdisk command is as follows:
sfdisk –d /dev/sdb | sfdisk /dev/sda
Warning: be careful to specify the right source and destinations drives when using sfdisk or your could blank out the partition table on your good drive.
Once the partitions have been created, you can add them to the corresponding RAID devices using “mdadm –add” commands. For example:
mdadm –add /dev/md0 /dev/sda1
mdadm –add /dev/md1 /dev/sda2
Once added, the Linux kernel immediately starts re-syncing contents of the arrays onto the new drive. You can monitor progress via “cat /proc/mdstat”. Syncing uses idle CPU cycles to avoid overloading a production system, so performance should not be affected too badly. The busier the server (and larger the partitions), the longer the re-sync will take.
You don’t have to wait until all partitions are re-synced… servers can be on-line and in production while syncing is in progress: no data will be lost and eventually all drives will become synchronized.
Summary
Linux software RAID is far more cost effective and flexible than hardware RAID, though it is more complex and requires manual intervention when replacing drives. In most situations, software RAID performance is as good (and often better) than an equivalent hardware RAID solution, all at a lower cost and with greater flexibility. When all you need are mirrored drives, software RAID is often the best choice.
More information on Linux RAID:
Related posts:
Tags: RAID
Posted by aionman on Feb 1, 2009 in
Linux,
Ubuntu
http://www.ubuntugeek.com/ubuntu-804-hardy-heron-lamp-server-setup.html
Webmin is a web-based interface for system administration for Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and much more. Webmin removes the need to manually edit Unix configuration files like /etc/passwd, and lets you manage a system from the console or remotely.
You can install webmin for your server web interface to configure apache,mysql servers.Now we will see how to install webmin in Ubuntu 8.04
Preparing your system
First you need to install the following packages
sudo apt-get install perl libnet-ssleay-perl openssl libauthen-pam-perl libpam-runtime libio-pty-perl libmd5-perl
Now download the latest webmin using the following command
wget http://prdownloads.sourceforge.net/webadmin/webmin_1.420_all.deb
Now we have webmin_1.420_all.deb package install this package using the following command
sudo dpkg -i webmin_1.420_all.deb
This will complete the installation.
Ubuntu in particular don’t allow logins by the root user by default. However, the user created at system installation time can use sudo to switch to root. Webmin will allow any user who has this sudo capability to login with full root privileges.
Now you need to open your web browser and enter the following
https://your-server-ip:10000/
