Hello, I am experiencing very slow conversion from single disk BTRFS to raid1 balanced (new disk was added): what I have done: I have added new disk to nearly full (cca 85%) BTRFS filesystem on LVM volume with intention to convert it into raid1: btrfs balance start -dconvert raid1 -mconvert raid1 /data/ > Jan 10 08:14:04 sopa kernel: [155893.485617] BTRFS info (device dm-0): > disk added /dev/sdb3 > Jan 10 08:15:06 sopa kernel: [155955.958561] BTRFS info (device dm-0): > relocating block group 2078923554816 flags data > Jan 10 08:15:07 sopa kernel: [155956.991293] BTRFS info (device dm-0): > relocating block group 2077849812992 flags data > Jan 10 08:15:10 sopa kernel: [155960.357846] BTRFS info (device dm-0): > relocating block group 2076776071168 flags data > Jan 10 08:15:13 sopa kernel: [155962.772534] BTRFS info (device dm-0): > relocating block group 2075702329344 flags data > Jan 10 08:15:14 sopa kernel: [155964.195237] BTRFS info (device dm-0): > relocating block group 2074628587520 flags data > Jan 10 08:15:45 sopa kernel: [155994.546695] BTRFS info (device dm-0): > relocating block group 2062817427456 flags data > Jan 10 08:15:52 sopa kernel: [156001.952247] BTRFS info (device dm-0): > relocating block group 2059596201984 flags data > Jan 10 08:15:58 sopa kernel: [156007.787071] BTRFS info (device dm-0): > relocating block group 2057448718336 flags data > Jan 10 08:16:00 sopa kernel: [156010.094565] BTRFS info (device dm-0): > relocating block group 2056374976512 flags data > Jan 10 08:16:06 sopa kernel: [156015.585343] BTRFS info (device dm-0): > relocating block group 2054227492864 flags data > Jan 10 08:16:12 sopa kernel: [156022.305629] BTRFS info (device dm-0): > relocating block group 2051006267392 flags data > Jan 10 08:16:23 sopa kernel: [156033.373144] BTRFS info (device dm-0): > found 75 extents > Jan 10 08:16:29 sopa kernel: [156038.666672] BTRFS info (device dm-0): > found 75 extents > Jan 10 08:16:36 sopa kernel: [156045.909270] BTRFS info (device dm-0): > found 75 extents > Jan 10 08:16:42 sopa kernel: [156052.292789] BTRFS info (device dm-0): > found 75 extents > Jan 10 08:16:46 sopa kernel: [156055.643452] BTRFS info (device dm-0): > found 75 extents > Jan 10 08:16:54 sopa kernel: [156063.608344] BTRFS info (device dm-0): > found 75 extents after 6hours of processing with 0% progress reported by balance status, I decided to cancel it to empty more space and rerun balance with some filters: btrfs balance cancel /data > Jan 10 14:38:11 sopa kernel: [178941.189217] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:38:14 sopa kernel: [178943.619787] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:38:20 sopa kernel: [178950.275334] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:38:24 sopa kernel: [178954.018770] INFO: task btrfs:30196 > blocked for more than 845 seconds. > Jan 10 14:38:24 sopa kernel: [178954.018844] > btrfs_cancel_balance+0xf8/0x170 [btrfs] > Jan 10 14:38:24 sopa kernel: [178954.018878] > btrfs_ioctl+0x13af/0x20d0 [btrfs] > Jan 10 14:38:28 sopa kernel: [178957.999108] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:38:29 sopa kernel: [178958.837674] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:38:30 sopa kernel: [178959.835118] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:38:31 sopa kernel: [178960.915305] BTRFS info (device dm-0): > found 68 extents > Jan 10 14:40:25 sopa kernel: [179074.851376] > btrfs_cancel_balance+0xf8/0x170 [btrfs] > Jan 10 14:40:25 sopa kernel: [179074.851408] > btrfs_ioctl+0x13af/0x20d0 [btrfs] now nearly 4 days later (and after some data deleted) both balance start and balance cancel processes are still running and system reports: > root@sopa:/var/log# btrfs balance status /data/ > Balance on '/data/' is running, cancel requested > 0 out of about 1900 chunks balanced (29 considered), 100% left > root@sopa:~# uname -a > Linux sopa 5.4.8-050408-generic #202001041436 SMP Sat Jan 4 19:40:55 > UTC 2020 x86_64 x86_64 x86_64 GNU/Linux > > root@sopa:~# btrfs --version > btrfs-progs v4.15.1 > > root@sopa:~# btrfs fi show > Label: 'SOPADATA' uuid: 37b8a62c-68e8-44e4-a3b2-eb572385c3e8 > Total devices 2 FS bytes used 1.04TiB > devid 1 size 1.86TiB used 1.86TiB path /dev/mapper/sopa-data > devid 2 size 1.86TiB used 0.00B path /dev/sdb3 > > root@sopa:~# btrfs subvolume list /data > ID 1021 gen 7564583 top level 5 path nfs > ID 1022 gen 7564590 top level 5 path motion > root@sopa:~# btrfs fi df /data > Data, single: total=1.84TiB, used=1.04TiB > System, DUP: total=8.00MiB, used=224.00KiB > System, single: total=4.00MiB, used=0.00B > Metadata, DUP: total=6.50GiB, used=2.99GiB > Metadata, single: total=8.00MiB, used=0.00B > GlobalReserve, single: total=512.00MiB, used=0.00B > is it normal that it have written nearly 5TB of data to the original disk ??: > root@sopa:/var/log# ps ax | grep balance > 16014 ? D 21114928:30 btrfs balance start -dconvert raid1 > -mconvert raid1 /data/ > 30196 ? D 0:00 btrfs balance cancel /data > root@sopa:/var/log# cat /proc/16014/io | grep bytes > read_bytes: 1150357504 > write_bytes: 5812039966720 > root@sopa:/sys/block# cat /sys/block/sdb/sdb3/stat > 404 0 39352 956 4999199 1016 40001720 > 71701953 0 14622628 67496136 0 0 0 0 > [520398.089952] btrfs(16014): WRITE block 131072 on sdb3 (8 sectors) > [520398.089975] btrfs(16014): WRITE block 536870912 on sdb3 (8 sectors) > [520398.089995] btrfs(16014): WRITE block 128 on dm-0 (8 sectors) > [520398.090021] btrfs(16014): WRITE block 131072 on dm-0 (8 sectors) > [520398.090040] btrfs(16014): WRITE block 536870912 on dm-0 (8 sectors) > [520398.154382] btrfs(16014): WRITE block 14629168 on dm-0 (512 sectors) > [520398.155017] btrfs(16014): WRITE block 17748832 on dm-0 (512 sectors) > [520398.155545] btrfs(16014): WRITE block 17909352 on dm-0 (512 sectors) > [520398.156091] btrfs(16014): WRITE block 20534680 on dm-0 (512 sectors) > regards jn
