Please recommend best free tool for LINUX server restoration OS ONLY

DriveImageXML, Acronis TrueImage, Ghost..  Not all are free.

I think you may want to review here -
http://en.wikipedia.org/wiki/Comparison_of_disk_cloning_software

HTH,

Kent

I would go clonezilla, Mondo

-http://clonezilla.org/
Free (GPL) Software.
Filesystem supported: ext2, ext3, ext4, reiserfs, xfs, jfs of GNU/Linux, FAT, NTFS of MS Windows, and HFS+ of Mac OS. Therefore you can clone GNU/Linux, MS windows and Intel-based Mac OS, no matter it's 32-bit (x86) or 64-bit (x86-64) OS. For these file systems, only used blocks in partition are saved and restored. For unsupported file system, sector-to-sector copy is done by dd in Clonezilla.  LVM2 (LVM version 1 is not) under GNU/Linux is supported.  Multicast is supported in Clonezilla SE, which is suitable for massively clone. You can also remotely use it to save or restore a bunch of computers if PXE and Wake-on-LAN are supported in your clients.


-Mondo
http://www.mondorescue.org/
Mondo is comprehensive. Mondo supports LVM 1/2, RAID, ext2, ext3, ext4, JFS, XFS, ReiserFS, VFAT, and can support additional filesystems easily: just e-mail the mailing list with your request. It supports software raid as well as most hardware raid controllers. It supports adjustments in disk geometry, including migration from non-RAID to RAID. Mondo runs on all major Linux distributions (RedHat, RHEL, SuSE, SLES, Mandriva, Debian, Gentoo) and is getting better all the time. You may even use it to backup non-Linux partitions, such as NTFS. Mondo is free! It has been published under the GPL v2 (GNU Public License), partly to expose it to thousands of potential beta-testers but mostly as a contribution to the Linux community.

Depends on what you're backing up to.  I know I won't get much love for it here, but here goes:

for disk backups ->  DD or tar\gzip
for tape backups ->  Dump\Restore

Thank you all - Please help me with below also:

1. LVM Snapshots - can it be useful - i never used?
2. Amanda Backups?

LVM snapshots are good for backing up application data in environments where the application must be shut down to get a consistent backup but where an application downtime  during the whole backup process is not an option.

I don't think you should not use LVM snapshot backups for crash recovery - there might be referential integrity problems, because initiation of snapshots on all of the logical volumes at the same time in an "atomic" manner seems hardly possible.

As far as I know Amanda is something like a wrapper around "tar" and is not capable of taking disk images.
There might be tricks to use it for bare metal recovery, but I wouldn't recommend such things.

Personal/Home use or Enterprise?
How much data are you talking about?
Where is it going? Onsite? Offsite?

LVM is sort of irrelevant if you use it or not.

Clonezilla is fine for most things linuxy but you should backup the OS anyway.

For reference:
I have a clonezilla image done once per month and backup eveything to network disk as tar, I recover using a rescue disk as I find it easier but have a clonezilla image if I need it. The servers I backup are not large and the data is not important in the grand scheme of things, that is the company wont disappear if it takes ages to get the servers back and if they dont come back at all it would just be annoying.

On the other end of the scale we have a large tivoli setup which does everything but cost the earth.

Basically, find something that works for you, be it tar or clonezilla or something else, backup and test restores and document it all. If this is for a customer tell them not to be stingy and invest the money if the data is important enough to warrant it.

Thank you