Still on my btrfs-based backup system. I still see one BUG() reached in btrfs-fixup per boot time, no memory exhaustion anymore. There is now however something new: write performance is down to a few bytes per second.
I've got a few processes (rsync, patched ntfsclone, shells mostly) writing to files at the same time on this server. disk stats per second: --dsk/sda-----dsk/sdb-----dsk/sdc-- read writ: read writ: read writ 264k 44k: 193k 44k: 225k 42k 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 60k: 0 0 : 0 0 0 12k: 0 1176k: 0 1164k 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 40k: 0 0 :8192B 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 :4096B 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 324k 0 : 248k 0 : 548k 0 0 4096B: 0 0 : 0 0 352k 0 : 0 0 : 0 0 0 0 : 0 0 : 0 0 0 0 : 0 0 :4096B 0 0 0 : 0 0 : 0 0 0 80k: 0 0 : 0 0 rsync: # strace -Ts0 -p 5015 Process 5015 attached - interrupt to quit write(3, ""..., 1024) = 1024 <0.007700> write(3, ""..., 1024) = 1024 <0.015822> write(3, ""..., 1024) = 1024 <0.031853> write(3, ""..., 1024) = 1024 <0.015881> write(3, ""..., 1024) = 1024 <0.015911> write(3, ""..., 1024) = 1024 <0.015796> write(3, ""..., 1024) = 1024 <0.031946> write(3, ""..., 1024) = 1024 <4.083854> write(3, ""..., 1024) = 1024 <0.007925> write(3, ""..., 1024) = 1024 <0.003776> write(3, ""..., 1024) = 1024 <0.031862> write(3, ""..., 1024) = 1024 <0.011807> write(3, ""..., 1024) = 1024 <0.019742> write(3, ""..., 1024) = 1024 <0.015857> write(3, ""..., 1024) = 1024 <0.031833> write(3, ""..., 1024) = 1024 <0.015789> write(3, ""..., 1024) = 1024 <0.015926> write(3, ""..., 1024) = 1024 <4.095967> write(3, ""..., 1024) = 1024 <0.019798> write(3, ""..., 1024) = 1024 <4.083682> write(3, ""..., 1024) = 1024 <0.015398> write(3, ""..., 1024) = 1024 <0.015951> write(3, ""..., 1024) = 1024 <0.035837> write(3, ""..., 1024) = 1024 <0.015962> write(3, ""..., 1024) = 1024 <0.015909> write(3, ""..., 1024) = 1024 <0.015967> write(3, ""..., 48) = 48 <0.003782> write(3, ""..., 1024) = 1024 <0.031802> write(3, ""..., 1024) = 1024 <0.015811> write(3, ""..., 1024) = 1024 <0.015944> write(3, ""..., 1024) = 1024 <0.019810> write(3, ""..., 1024) = 1024 <0.031948> ntfsclone (patched to only write modified clusters): # strace -Te write -p 4717 Process 4717 attached - interrupt to quit write(1, " 65.16 percent completed\r", 25) = 25 <0.008996> write(1, " 65.16 percent completed\r", 25) = 25 <0.743358> write(1, " 65.16 percent completed\r", 25) = 25 <0.306582> write(1, " 65.17 percent completed\r", 25) = 25 <4.082723> write(1, " 65.17 percent completed\r", 25) = 25 <0.006402> write(1, " 65.17 percent completed\r", 25) = 25 <0.012582> write(1, " 65.17 percent completed\r", 25) = 25 <4.052504> write(1, " 65.17 percent completed\r", 25) = 25 <0.012111> write(1, " 65.17 percent completed\r", 25) = 25 <0.016001> write(1, " 65.17 percent completed\r", 25) = 25 <4.028017> write(1, " 65.18 percent completed\r", 25) = 25 <0.013365> write(1, " 65.18 percent completed\r", 25) = 25 <0.003963> (that's writing to a log file) See how many write(2)s take 4 seconds. No issue when writing to an ext4 FS. SMART status on all drives OK. What else could I look at? Attached is a sysrq-t output. -- Stephane
sysrq-t.txt.xz
Description: Binary data
