I'm trying to debug performance issues on a SmartOS joyent_20140613T024634Z
server that is running netatalk in a zone.
After some investigation with the help of netatalk developer Ralph Böhme, I
find that the netatalk afpd is spending a very long time in the syscall
getcwd()
in some cases. Ralph provided a Dtrace script which breaks down the time spent
in various syscalls, and getcwd() seems to be the major bottleneck here. I've
attached an excerpt of the Dtrace analysis below.
Is there any reason why getcwd() should take a long time? Disk I/O does not
appear to be an issue. For reference, I got similar results before and after
starting a zpool scrub on the zones pool, and the scrub is proceeding at 940
MB/s.
Further background on the issue is discussed here:
<http://sourceforge.net/p/netatalk/mailman/message/32660961/>
and the full output of the Dtrace script is here:
<https://gist.github.com/ferebee/99016ccd293b3f616c77>
All sugestions are most welcome!
Thanks,
Chris
===== Quick details: =====
The server is a dual Xeon E5-2620 with 128 GB RAM, LSI 9211 SAS controller, 24
SAS disks in 12 x 2 mirrors + ZeusRAM, running SmartOS joyent_20140613T024634Z.
I compiled netatalk 3.1.2, and it works as expected except for a major slowdown
in the Finder of clients running OS X 10.9. While the slowdown is probably
triggered by inappropriate behavior of the Finder (which loops continually over
the AFP share, performing calls to
syscalls elapsed time average
=============================
getuid 0
lwp_sigmask 1
seteuid 1
fstat 2
close 3
fcntl 3
recv 3
setcontext 4
setitimer 5
unlink 11
acl 12
read 13
rmdir 14
getdents 15
open 17
send 18
writev 19
statvfs 31
openat 36
chdir 40
lstat 40
sendfilev 42
stat 48
pollsys 426
getcwd 94245
-------------------------------------------
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