Hi everybody,
I'm currently experiencing some heavy problems with my RAID 5 BTRFS.
Background:
I started with a ext4 RAID 1 (2 disks, 3TB)
One week ago I added one more disk and converted to RAID 5 (with some problems during conversion, but solved)
After that, I converted the ext4 file system to BTRFS and removed conversion snapshot.
Now the write speed of the RAID 5 is REALLY slow - even below 10 MB/s.
CPU load seems to be ok (about 20%).
dbench shows only ~0.01 MB/s:
Bash
[bbsan@omvserver volume1]$ dbench -D /media/b3183f09-e671-4dbe-b21f-d84fc12e9b97 -t 20 2
dbench version 4.00 - Copyright Andrew Tridgell 1999-2004
Running for 20 seconds with load '/usr/share/dbench/client.txt' and minimum warmup 4 secs
0 of 2 processes prepared for launch 0 sec
2 of 2 processes prepared for launch 0 sec
releasing clients
2 664 42.32 MB/sec warmup 1 sec latency 982.196 ms
2 664 21.16 MB/sec warmup 2 sec latency 1982.244 ms
2 664 14.11 MB/sec warmup 3 sec latency 2982.285 ms
2 664 0.00 MB/sec execute 1 sec latency 4982.337 ms
2 667 0.01 MB/sec execute 2 sec latency 5389.880 ms
2 667 0.00 MB/sec execute 3 sec latency 1592.540 ms
2 667 0.00 MB/sec execute 4 sec latency 2592.588 ms
2 667 0.00 MB/sec execute 5 sec latency 3592.632 ms
2 667 0.00 MB/sec execute 6 sec latency 4592.666 ms
2 667 0.00 MB/sec execute 7 sec latency 5592.727 ms
2 698 0.02 MB/sec execute 8 sec latency 5743.095 ms
2 698 0.02 MB/sec execute 9 sec latency 1404.055 ms
2 698 0.02 MB/sec execute 10 sec latency 2404.108 ms
2 698 0.01 MB/sec execute 11 sec latency 3404.164 ms
2 698 0.01 MB/sec execute 12 sec latency 4404.214 ms
2 723 0.02 MB/sec execute 13 sec latency 4996.759 ms
2 724 0.02 MB/sec execute 14 sec latency 1051.250 ms
2 724 0.02 MB/sec execute 15 sec latency 2051.286 ms
2 724 0.02 MB/sec execute 16 sec latency 3051.320 ms
2 724 0.02 MB/sec execute 17 sec latency 4051.372 ms
2 724 0.02 MB/sec execute 18 sec latency 5051.433 ms
2 724 0.02 MB/sec execute 19 sec latency 6051.478 ms
2 cleanup 20 sec
2 cleanup 21 sec
2 cleanup 22 sec
2 cleanup 23 sec
0 cleanup 24 sec
Operation Count AvgLat MaxLat
----------------------------------------
NTCreateX 20 1.447 28.737
Close 20 0.002 0.008
Rename 2 0.045 0.049
Unlink 2 0.382 0.735
Qpathinfo 8 0.003 0.006
Qfileinfo 5 0.003 0.006
Qfsinfo 6 0.113 0.168
Sfileinfo 4 81.523 326.061
Find 4 0.034 0.050
WriteX 24 4.503 102.366
ReadX 12 0.003 0.007
Flush 18 3032.779 10277.908
Throughput 0.015008 MB/sec 2 clients 2 procs max_latency=6051.478 ms
Alles anzeigen
mdstat:
Bash
[bbsan@omvserver volume1]$ cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md127 : active raid5 sdb[0] sda[3] sdc[2]
5860270080 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
unused devices: <none>
Any suggestions?