BTRFS Testing and use

[oshunluvr]

Re: BTRFS Testing and use

I haven't read anything about the fsck tool but I think they'll have to have one soon if they want to move btrfs higher in the food chain.

I'm using rdiff-backup which works very well. It can be very simple to use up to as complicated as you wish - incremental features and such. I am supposed to get it set up as a cron-job but I've been too busy lately. I admit I haven't had to restore anything yet, but the process seems simple enough.

Since I have a server with ample room, I back up from my desktop to the server and the important stuff on the server is backed up to my desktop. Drive space is cheap, even if you buy high performance large capacity drives. WD 2TB 6Gbs "Black" < $150

[oshunluvr]

Re: BTRFS Testing and use

I am in the process of removing one drive from my 4x500GB array but I can't get one of the three partitions that were in use to "delete." The other two worked as expected. I did force a re-balance after removing these. The delete process must be optimized for speed so it left a few 100MB more on one partition than the others, but no biggie, rebalancing worked well. One thing totally missing is any sort of feedback during these processes. A progress bar of some sort would be a welcome addition.

I also noticed one of the effects of re-balancing was the device reported a little more usable space afterword. I assume the re-balance forces some house keeping that might have been delayed during normal use.

On the one that keeps failing during delete, I get no real error messages and can't find enough documentation on-line to figure out what the next step should be. It gets about 20% of the data off and then just spits out an error and stops.

Very cool though that it seems to make no difference to the system. All data intact. I just rebalanced and everything went back to normal.

I attempted a defrag on the device that errors but it justs says "complete" and quits basically immediately. I don't know if it's not is fragmented or if the tool is not actually working.

BTRFS Scores so far:

Ease of use +2: Way easier to setup than RAID now that btrfs is in the kernel.
Error output -1: Difficult to troubleshoot without any help.
Process feedback 0: Not a necessity, but would be nice.
Speed +1: As fast as my RAID0 devices in daily use.
Flexability +3: You can actually add and remove space while mounted and without manually moving your data off the device first - absolutely amazing!
Damage recovery -2: Haven't need it yet, but keeping my fingers crossed is starting to hurt. An fsck tool has to be added soon IMO.

Areas yet to be utilized/tested:

Subvolumes: Unless you specify otherwise, the filesystem will actually automatically create a @home subvolume during install instead of the old way of just putting /home under root. This is way cool - makes it easier to create a home backup and create snapshots (see below) of just your data. What I would like to test is using subvolumes for a multiuser setup. Each user having their own subvolume instead of partition space.

The real power and beauty of subpartitions is no more partitioning! No re-partitioning, messing with partition tables, resizing and moving partitions, etc. One of your users filling up all your drive space? No problem - pop in a new drive, add it to your btrfs device, re-balance and you all have more room to grow. You never have to out-grow your partitions - they will grow with you!

Snapshots: I haven't researched or attempted to use this feature yet. But again - another huge potential labor and data saver. Rolling back data or recovering from failures is a much needed ability in many environments.

I would still advise anyone diving into btrfs to make full backups - but you should all know that by now.

I predict by Dec. 21st 2012 we will not see the end of the world but we might see the end of old fashioned partitioning and drive formatting!