I've partitioned my new 4.5TB drives this way:
I formatted the backup filesystem as ext3. This way, I can simply boot with a Fedora Live CD, mount the backup partition and backup my boot and root partitions to the backup. Of course, I'll need to roll that backup off to another storage media. But this strategy helps when I make major updates to my system because I can easily rollback to an earlier version that is stored locally.
Most importantly, restore works!
Here's what I did the other day to get 'er going.
First, I booted to my Fedora Live CD. It didn't have fsarchiver installed by default, so I did so. You need to become superuser to do this:
[liveuser@localhost ~]$ su
[root@localhost liveuser]# yum install fsarchiver
Loaded plugins: presto, refresh-packagekit
Setting up Install Process
--> Running transaction check
---> Package fsarchiver.i686 0:0.6.7-1.fc12 set to be updated
--> Finished Dependency Resolution
Package Arch Version Repository Size
fsarchiver i686 0.6.7-1.fc12 updates 93 k
Install 1 Package(s)
Upgrade 0 Package(s)
Total download size: 93 k
Is this ok [y/N]: y
Transaction Test Succeeded
Installing : fsarchiver-0.6.7-1.fc12.i686 1/1
I created my backup directory and mounted it:
[root@localhost liveuser]# mkdir /mnt/backup
[root@localhost liveuser]# mount -t ext3 /dev/mapper/vg_ogre-lv_backup /mnt/backup
[root@localhost liveuser]# ls /mnt/backup
Finally, I ran fsarchiver to do the backup and took advantage of its multithreaded capability:
[root@localhost liveuser]# fsarchiver -j7 -o savefs /mnt/backup/lv_root_backup.fsa /dev/mapper/vg_ogre-lv_root
Statistics for filesystem 0
* files successfully processed:....regfiles=306990, directories=31024, symlinks=16561, hardlinks=4157, specials=28
* files with errors:...............regfiles=0, directories=0, symlinks=0, hardlinks=0, specials=0
You could concatenate these steps into a script:
[mule@ogre ~]$ cat systemBackup.sh
yum install fsarchiver
mount -t ext3 /dev/mapper/vg-ogre/lv_backup /mnt/backup
fsarchiver -j7 -o savefs /mnt/backup/lv_root_backup.fsa /dev/mapper/vg_ogre-lv_root
Voila! In seven hours, I backed up approximately 450GB of data:
[root@localhost liveuser]$ ll /mnt/backup
drwx------. 2 root root 16384 2010-02-10 20:09 lost+found
-rw-r--r--. 1 root root 480252970629 2010-07-21 07:34 lv_root_backup.fsa
When my RAID set was not being checked, an fsarchive of about 760GB took 3.5 hours. Not bad!
Restore works in a similar way. Since fsarchiver allows you to backup multiple filesystems within one archive, you need to specify which filesystem is getting restored.
In the example below, the "id=0" specifies the index (starting at 0) of the filesystem that is in the archive. The filesystem to be restored cannot be mounted:
fsarchiver restfs /mnt/backup/lv_root_backup.fsa id=0,dest=/dev/mapper/vg_ogre-lv_root
If you had multiple file systems stored in the archive "lv_root_backup.fsa", then the id number would increment; eg, "id=1" for the second filesystem stored in the archive.
"dest" is the destination filesystem which is getting restored, in this case "/dev/mapper/vg_ogre-lv_root"
Password Protection for Archives
You can also specify a password to password protect your archive. On backup and restore, the password switch looks the same:
sudo fsarchiver restfs backup_vg_ogre-lv_root.fsa id=0,dest=/dev/sdb1 -c [password]
Worked for me on many occasions.