2013/06/20

Linux System Recovery using Symantec Netbackup and a Linux Live-CD


The aim here is to describe a Linux System Recovery using Linux Live-CD and Symantec Netbackup Backup. Before delving into technical details, we want to highlight the fact that Symantec Netbackup has a Bare Metal Recovery features that suit this type of Recovery. But this feature doesn’t support all Linux OS (most of the popular ones are supported). For instance, this procedure was used to restored a complete Redhat 9 :)  Installation (it can also be used for a P2V migration).

Let’s check what is required for such restoration.

1.   A valid Full Symantec Netbackup Backup of the system we're trying to restore(I guess that one is obvious)
2.   A Linux Live CD that can support Symantec Netbackup Client, we’re using Ubuntu 8.04 LTS in this guide (fully supported, a list of supported OS can be found here)
3.  The installation CD of the Distribution we’re restoring, as stated above, we’re restoring a Redhat 9. So a Redhat 9 Boot CD is what we need for this case. The main reason for having the Install CD of the distribution is to avoid some incompatibility (like creating a filesystem which isn’t supported by the maintenance tools –e.g fsck- of the restored system)
4.  An Internet Connection (though it isn’t mandatory, we may just need some softwares/packages to install before installing Symantec Netbackup Client)

Once these prerequisites are met, we’re ready to start our restoration. As already described above, for this post, we’re using Ubuntu 8.04 LTS as Live-CD and are restoring a Redhat 9 Installation (the procedure can be easily adapted to others Distribution).

Below, a step-by-step (from a to f) description

a.     Boot on the Redhat 9 CD in rescue mode (linux rescue at the prompt) and recreate the target filesystems (the ones which will contain the restored data). Below is what we’ll create during this step.

MountPoint
Size
Filesystem
Device
/
65 GB
Ext3
/dev/sda3
/boot
100 MB
Ext3
/dev/sda1
/var
65 GB
Ext3
/dev/sda2
Swap
10 GB
Swap
/dev/sda5

Note that the target filesystems could be re-sized during this step (as long as we give enough space for the restoration). It’s also important to create these filesystems using the operating system we’re going to restore (avoid some filesystems features incompatibilities).

We just need a shell at this stage, so we’ll choose skip during the step in the screenshot below.



The filesystems are then created using fdisk and mkfs.ext3, mkswap… (as usual)


b.     Reboot the system on the Ubuntu Live-CD and install the required software for Netbackup Client Installation.
I assume that the network connectivity for Internet Connection and Software Installation is done for the Ubuntu LiveCD System. The list of software required to install on Netbackup Client for Supported Ubuntu/Debian can be found here. For proper NetBackup client operation on Ubuntu 8.04 Server Edition (64bit) the following packages are needed:

-  ia32-libs (In Universe Repository, so universe repository was enabled)
-  xinetd
-  ssh-server/rsh-server (required for remote install only)

We’ve also added the following for our specific environment

-  nfs-common (required to mount the directory where we’re keeping Netbackup Client binaries)
-  autofs (use to automatically mount the NFS shares)



Let’s also configured autofs to use /net automount features and complete Netbackup Client Installation.



c.     After the prerequisites, we’re adding Netbackup servers entries to the /etc/hosts files, add the Ubuntu Client Entries in Netbackup Servers hosts file, Install the client and register the Ubuntu LiveCD node.


On Ubuntu LiveCD,









On Master/Media Netbackup Servers,








d.     We can now mount the filesystems that were previously created (step a.) in the directory where we’ll push the restoration







e.     Let’s the restoration begin (using Netbackup Java Console, specifying as source the system to restore and as destination our Ubuntu Server, choose “restore everything to different location” and fill with the name of the directory where / is mounted)







Choose the last full you want to recover from the backup history and start the / restoration.











Uncheck  the rename soft/hard link options that are enabled by default.




f.      After the restoration, we can reboot the system and fix the Specific Operating Systems Issues that will arise. In this case, we’ve to do the following:



1.     Reinstall the Grub, for that we’re going through the “linux rescue” using Redhat 9 CD. We’ll let the rescue mode trying to mount the restored system under /mnt/sysimage. If not able, mount the filesystem manually and chroot under the mounted directory




2.     Modify the /etc/modules.conf to add Vmware scsi controller driver by replacing the following in /etc/modules.conf

# alias scsi_hostadapter mptbase
# alias scsi_hostadapter1 mptscsih


3.     Recreate the initrd which will now have the correct scsi modules



4.     I found that my etc/fstab was set to use e2label , so label were well reassigned to each filesystem