pvaneynd

Now that my server at home is running FreeBSD on top of ZFS for a while now I though to setup the backups again.

Now I have 3 disks in the server, 2 are reliable and are used in the main ZFS pool (zroot), one is a POC WD 'green' disk that will die if you use it too often. So that one is my local backup disk.

My backup strategy is that I configured daily snapshots on zroot, I have the local backup disk and I'm using a USB hard disk for off-site backups.

At first I thought to use UFS2 on the third disks with rsync, like I did with Linux. Then I read a bit more about the ZFS functions and decided to use ZFS on the third disk. I created a 'fastbackup' pool and then used zfs send and zfs receive to sync the two pools. Syncing the disks was fast. Very fast indeed, about as fast as a simple 'dd' would have been.

However ZFS's magic does not end here. It has the option of sending incremental changes that happened between snapshots. So I wrote a script that makes a new snapshot ("nu" now in Dutch), sends the incremental changes to 'fastbackup' and then moved the reference snapshot forward. This to me seemed to be faster then using rsync. which would always take at least 5 minutes to declare that the filesystems were in sync. ZFS is ... faster:

+ zfs snapshot zroot/usr@nu
+ zfs send -vi zroot/usr@laatste zroot/usr@nu
+ zfs receive -Fv fastbackup/usr@nu
receiving incremental stream of zroot/usr@nu into fastbackup/usr@nu
received 597MB stream in 10 seconds (59.7MB/sec)

So that's a day worth of changes, including building and installing emacs and clisp, in 10 seconds.

Script I used below the cut.( fastbackup.sh )

- a fuse can break
- it is most likely to do so just when people come to see if they want to buy your house
- a lamp has almost 0 resistance so you can check the wiring from the fuse box
- FreeBSD does not know lvm or dm so it is not so easy to copy information across
- fuse-zfs is not good enough to mount the FreeBSD zfs partitions
- the intel BIOS on my PC will not boot from a disk when no partition is marked as active
- installing FreeBSD mbr on a 2T disk fails, using ZFS on GPT works.


Open questions:
- I can install packages with "pkg_add -r <foo>", but how can I check for updates and update them?