@Noggin Thanks for the update and glad it worked out in the end:
quotas on performance is under much scrutiny / development by the btrfs folks and there are a few fairly significant improvements in the pipelines. Hopefully we will run into these sooner rather than later.
Yes that looks a little happier. During balance the figures can look pretty strange as some space is used for the operation itself. Also note that what you are looking at is allocated space, and not actual usage from data (even though in btrfs fi show is states usage confusingly). Btrfs first allocates chunks (shown by fi show), which have individual raid profiles and sizes each of mostly 1GB. Chunks are created/allocated on an as needed basis. These chunks are then populated by much smaller ‘blocks’ which inherit their parent chunks raid levels. So in a balance that involves a raid change there is quite a to-do list with all the shuffling required to create the new raid level chunks and move the associated blocks from their old raid level chunks to their new ones. I’ve probably butcher that but it may help.
Anyway, as to the fi show ‘usage’ which is actually allocation (of chunks) see the following command and you may note another reason why raid5/6 is not recommended just yet:
btrfs fi usage /mnt2/main_pool
This will show both allocated (fi show ‘usage’) and it’s own ‘Used’ variant which I’m pretty sure pertains to the sum of blocks within chunks.
You can also examine a single drive independently with that command. Rockstor uses that command internally as well as in combination with fi show and some subvol bits and bobs.
We have a pending pull request of mine that @Flox has kindly functionally reviewed that surfaces the per disk allocation that you were watching in your btrfs fi show reports during this balance as it’s often a useful indicator. It also adds btrfs dev ids in the same pool details ‘Disks’ table. See the pics of the testing done prior to submitting that pull request that’s also the fix for the error you ran into in a previous forum thread re Web-UI leaving us high and dry on disk removals (read falling on it’s face):
As part of that fix I had to add better internal monitoring so though I’d surface it as well. Due to be released as 3.9.2-49 once I’m done with a back-end support project for stable subscribers; if all goes to plan that is .
Would be interesting to have the above fi usage output pasted here also if you fancy?
Thanks for the updates and glad your conversion seems to have worked out. What make/model of UPS are you using by the way and do you have it directly connect to the Rockstor machine? I use a Riello Sentinel Pro 1000 (SEP 1000) 1000VA / 800W. The NUT driver needs some work, last I looked, but I’ll try and chip in there if I ever get that amount of time. Maybe once our transition to openSUSE has calmed down.