On 01/26/2016 09:20 PM, Chris Murphy wrote:

nyway,
it seems reasonable to try a balance without the filters to see if
that's a factor, because those filters are brand new in btrfs-progs
4.4. Granted, I'd expect they've been tested by upstream developers,
but I don't know if there's an fstest for balance with these specific
filters yet.

I have another box with 8 disks RAID6 on which I simply did a balance
with no newly added drives. Same issue ... VERY slow running balance
with IO nowhere near 100% utilization and many many days of runtime to
finish.


Regards

Christian