Continous disk activity

Support
21

I tried strace as an alternative. Used it to trace the io of the child proces. Despite it show that there are a lot of read operations, it does not show the filename.

root@somehost:/volume1/homes/dataadmin/inotail-master# ps -ef | grep -i syncthing
syncthi+ 25024     1  0 15:23 ?        00:00:00 /usr/local/syncthing/bin/syncthing -home=/usr/local/syncthing/var
syncthi+ 25031 25024 93 15:23 ?        00:29:07 /usr/local/syncthing/bin/syncthing -home=/usr/local/syncthing/var
root     28414 22869  0 15:54 pts/9    00:00:00 grep --color=auto -i syncthing
root@somehost:/volume1/homes/dataadmin/inotail-master# strace -tt -f -v -p 25031 -e trace=read,write 
Process 25031 attached with 18 threads
[pid 25039] 13:54:34.716994 read(0, "", 0) = 0
[pid 25039] 13:54:34.718098 read(0, "", 0) = 0
[pid 25039] 13:54:34.719058 read(0, "", 0) = 0
[pid 25039] 13:54:34.719864 read(0, "", 0) = 0
[pid 25039] 13:54:34.720643 read(0, "", 0) = 0
[pid 25039] 13:54:34.721668 read(0, "", 0) = 0
[pid 25039] 13:54:34.722652 read(0, "", 0) = 0
[pid 25039] 13:54:34.723551 read(0, "", 0) = 0
[pid 25039] 13:54:34.724528 read(0, "", 0) = 0
[pid 25039] 13:54:34.725446 read(0, "", 0) = 0
[pid 25134] 13:54:34.729939 read(0, "", 0) = 0
[pid 25037] 13:54:34.915697 read(0, "", 0) = 0
[pid 25037] 13:54:34.916019 write(0, "", 0) = 0
[pid 26736] 13:54:34.917012 write(0, "", 0) = 0
[pid 25039] 13:54:34.948015 read(0, "", 0) = 0
[pid 25039] 13:54:34.949197 read(0, "", 0) = 0
[pid 25039] 13:54:35.046438 read(0, "", 0) = 0
[pid 25039] 13:54:35.148006 read(0, "", 0) = 0
[pid 25039] 13:54:35.367346 read(0, "", 0) = 0
[pid 25039] 13:54:35.484810 read(0, "", 0) = 0
[pid 25039] 13:54:35.485527 read(0, "", 0) = 0
[pid 25039] 13:54:35.486211 read(0, "", 0) = 0
[pid 25039] 13:54:35.486985 read(0, "", 0) = 0
[pid 25039] 13:54:35.487742 read(0, "", 0) = 0
[pid 25039] 13:54:35.488452 read(0, "", 0) = 0
[pid 25039] 13:54:35.489119 read(0, "", 0) = 0
[pid 25039] 13:54:35.489856 read(0, "", 0) = 0
[pid 25039] 13:54:35.490525 read(0, "", 0) = 0
[pid 25039] 13:54:35.491271 read(0, "", 0) = 0
[pid 25039] 13:54:35.491980 read(0, "", 0) = 0
[pid 25039] 13:54:35.764636 read(0, "", 0) = 0
[pid 25039] 13:54:35.765605 read(0, "", 0) = 0
[pid 25039] 13:54:35.766526 read(0, "", 0) = 0
[pid 26737] 13:54:35.801573 read(0, "", 0) = 0
[pid 25039] 13:54:35.820744 read(0, "", 0) = 0
[pid 25039] 13:54:35.964490 read(0, "", 0) = 0
[pid 25039] 13:54:35.965367 read(0, "", 0) = 0
[pid 25039] 13:54:35.966161 read(0, "", 0) = 0
[pid 25039] 13:54:35.966944 read(0, "", 0) = 0
[pid 25039] 13:54:35.967713 read(0, "", 0) = 0
[pid 25039] 13:54:35.986043 read(0, "", 0) = 0
[pid 25039] 13:54:35.987007 read(0, "", 0) = 0
[pid 25039] 13:54:35.987957 read(0, "", 0) = 0
[pid 25039] 13:54:35.988871 read(0, "", 0) = 0
[pid 25039] 13:54:35.989982 read(0, "", 0) = 0
[pid 25039] 13:54:36.003508 read(0, "", 0) = 0
[pid 25039] 13:54:36.004613 read(0, "", 0) = 0
[pid 25039] 13:54:36.005606 read(0, "", 0) = 0
[pid 25039] 13:54:36.006528 read(0, "", 0) = 0
[pid 25039] 13:54:36.007416 read(0, "", 0) = 0
[pid 25039] 13:54:36.140399 read(0, "", 0) = 0
[pid 25039] 13:54:36.141304 read(0, "", 0) = 0
[pid 25039] 13:54:36.142030 read(0, "", 0) = 0
[pid 25039] 13:54:36.142974 read(0, "", 0) = 0
[pid 25039] 13:54:36.143860 read(0, "", 0) = 0
[pid 25039] 13:54:36.144836 read(0, "", 0) = 0
[pid 25039] 13:54:36.203338 read(0, "", 0) = 0
[pid 25039] 13:54:36.204057 read(0, "", 0) = 0
[pid 25039] 13:54:36.204795 read(0, "", 0) = 0
[pid 25039] 13:54:36.205504 read(0, "", 0) = 0
[pid 25039] 13:54:36.361964 read(0, "", 0) = 0
22

hmmm… read operations from /dev/null ?!

root@somehost:/volume1/homes/dataadmin/inotail-master# strace -tt -f -v -y -p 25031 -e trace=read,write 
Process 25031 attached with 18 threads
[pid 25152] 14:00:31.141719 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.142614 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.143348 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.144013 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.144703 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.145388 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.146031 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.147020 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.147646 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.148545 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.149193 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.150074 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.150724 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.151643 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.152341 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.153219 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.282958 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.296119 read(0</dev/null>, "", 0) = 0
[pid 25152] 14:00:31.296988 read(0</dev/null>, "", 0) = 0
23

And when listing the fd for process 25031 i do get about 105 filedescriptors to the database.

root@somehost:/volume1/homes/dataadmin/inotail-master# ls -1lF /proc/25031/fd/ | grep volume1 | wc -l
105
root@somehost:/volume1/homes/dataadmin/inotail-master# ls -1lF /proc/25031/fd/
total 0
lr-x------ 1 syncthing users 64 Oct 21 16:07 0 -> /dev/null
l-wx------ 1 syncthing users 64 Oct 21 16:07 1 -> pipe:[7577787]
lr-x------ 1 syncthing users 64 Oct 21 16:07 10 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008082.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 100 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1986414.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 101 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1995566.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 102 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008502.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 103 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008527.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 104 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008623.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 105 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2007605.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 106 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2006923.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 107 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1986506.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 108 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1991624.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 109 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1998294.ldb
lrwx------ 1 syncthing users 64 Oct 21 16:07 11 -> socket:[7594401]
lr-x------ 1 syncthing users 64 Oct 21 16:07 110 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1998296.ldb
lrwx------ 1 syncthing users 64 Oct 21 16:07 111 -> socket:[7598362]
lr-x------ 1 syncthing users 64 Oct 21 16:07 112 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2007719.ldb
lrwx------ 1 syncthing users 64 Oct 21 16:07 113 -> socket:[7602730]
lrwx------ 1 syncthing users 64 Oct 21 16:07 114 -> socket:[7598324]
lrwx------ 1 syncthing users 64 Oct 21 16:07 115 -> socket:[7598325]
lr-x------ 1 syncthing users 64 Oct 21 16:07 116 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2005660.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 117 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1998301.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 118 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1978133.ldb
lrwx------ 1 syncthing users 64 Oct 21 16:07 119 -> socket:[7598332]
lr-x------ 1 syncthing users 64 Oct 21 16:07 12 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008083.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 120 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008096.ldb
lrwx------ 1 syncthing users 64 Oct 21 16:07 122 -> socket:[7663462]
lr-x------ 1 syncthing users 64 Oct 21 16:07 13 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008095.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 14 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1977906.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 15 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008100.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 16 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2007893.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 17 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1998299.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 18 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/2008257.ldb
lr-x------ 1 syncthing users 64 Oct 21 16:07 19 -> /volume1/@appstore/syncthing/var/index-v0.14.0.db/1877623.ldb
l-wx------ 1 syncthing users 64 Oct 21 16:07 2 -> pipe:[7577786]
24

In the strace cases it seems you are tracing monitor process that doesn’t do anything.

The open file descriptors are just pointing at the database files. You don’t need to trace file activity by process, you just need to trace it by directory, whether it happens in you data directory or syncthings database directories.

Given STTRACE=filesystem returns nothing during this high usage activity, I suspect it’s the latter.

25

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