I have tried to rebalance metadata..
Starting point:
# btrfs fi usage /storage
Overall:
Device size: 10.92TiB
Device allocated: 7.45TiB
Device unallocated: 3.47TiB
Device missing: 0.00B
Used: 7.35TiB
Free (estimated): 1.78TiB (min: 1.78TiB)
Data ratio: 2.00
Metadata ratio: 2.00
Global reserve: 512.00MiB (used: 0.00B)
Data,RAID1: Size:3.72TiB, Used:3.67TiB (98.74%)
/dev/sdc 2.81TiB
/dev/sdb 2.81TiB
/dev/sda 1017.00GiB
/dev/sdd 840.00GiB
Metadata,RAID1: Size:6.00GiB, Used:5.09GiB (84.86%)
/dev/sdc 3.00GiB
/dev/sdb 3.00GiB
/dev/sda 1.00GiB
/dev/sdd 5.00GiB
System,RAID1: Size:32.00MiB, Used:608.00KiB (1.86%)
/dev/sdb 32.00MiB
/dev/sdd 32.00MiB
Unallocated:
/dev/sdc 845.02GiB
/dev/sdb 845.99GiB
/dev/sda 845.02GiB
/dev/sdd 1017.99GiB
I did:
# btrfs fi resize 4:-2g /storage/
# btrfs balance start -mdevid=4 /storage
# btrfs fi resize 4:max /storage/
but the distribution of metadata ended up like before.
I also tried (to match the free space of the other disks):
# btrfs fi resize 4:-172g /storage/
# btrfs balance start -mdevid=4 /storage
# btrfs fi resize 4:max /storage/
again, the distribution of metadata ended up like before..
Any other tips to rebalance metadata ?
On 10-Apr-20 01:07, Zygo Blaxell wrote:
On Thu, Apr 09, 2020 at 11:53:00PM +0200, kjansen387 wrote:
btrfs fi resize 1:-1g /export; # Assuming 4GB metadata
btrfs fi resize 2:-2g /export; # Assuming 5GB metadata
Based on current data, yes; however, it's possible that the device remove
you are already running might balance the metadata as a side-effect.
Redo the math with the values you get after the device remove is done.
You may not need to balance anything.
btrfs balance start -mdevid=1 /export; # Why only devid 1, and not 2 ?
We want balance to relocate metadata block groups that are on both
devids 1 and 2, i.e. the BG has a chunk on both drives at the same time.
Balance filters only allow one devid to be specified, but in this case
'devid=1' or 'devid=2' is close enough. All we want to do here is filter
out block groups where one mirror chunk is already on devid 3, 4, or 5,
since that would just place the metadata somewhere else on the same disks.
btrfs fi resize 1:max /export;
btrfs fi resize 2:max /export;
Thanks!
