Tech Recipe for Backuppc

I will explain briefly how to move the Backuppc __TOP_DIR__ to another disk. The main reason of this long data processing is the performance improvement. I’ve tried several Filesystems and different under layer block device ( RAID5, RAID10) alwaysover LVM.

For the moment the best seems to be RAID10 with 32K chunksize and a reiserfs filesystem mounted with (notail,noatime) options.

The backup speed is not that much faster than on ext3 filesystem, but the main advantage of Reiserfs is that compare to ext3 the disk usage is reduced from 34G in ext3 to 27G in Reiserfs.

The next step will be to test Btrfs performance but for that I first need to migrate from kernel 2.6.18 to 2.6.28 or higher

So let start the recipe

Copy the real Files (the pool or cpool) to the new disk

I do prefer rsync but other method are possible (simple cp, tar, …)

cd /var/lib/backuppc rsync -aq --exclude=pc/ ./ /new_drive/new_backuppc/

be patient this can be long… to see what’s going on replace -aq by -avP

Use an Internal backuppc command (BackupPC_tarPCCopy) to copy each PC hardlinks structure

this is also very long treatement. A huge amount of small hardlinks are read and relinked to the new destination

su __BACKUPPCUSER__
cd NEW_TOPDIR
mkdir pc
cd pc
__INSTALLDIR__/bin/BackupPC_tarPCCopy __TOPDIR__/pc | tar xPf -


too keep an eye on the progress I’ve found a small tool pretty handy to monitor piped data: “bar”

/usr/share/backuppc/bin/BackupPC_tarPCCopy /var/lib/backuppc/pc | bar -dan -bs 4096 | tar xPf -

Here you are for the moment

Glad to hear any comment from your backup experience.

(article from http://blog.pepita.org/?p=249)