Recently, I started having problems with one of my newest servers ...
figuring that it might have somethign to do with the fact that I went SATA
for this one (all others are SCSI), I figured it might be a driver issue
causing the problems, since everything else is the same as the other 5
servers on our network ...
Today, I'm starting to wonder if I've been just looking at the "most
obvious" cause, instead of looking deeper ...
The problem that manifests itself is similar to the old 'ran out of vnode'
issue I used to experience under 4.x ... the server would still run, be
totally pingable, and you could even get the motd when you tried to ssh
in, but you couldn't get a prompt, and all processes were hung ...
I just upgraded the kernel on this machine (mercury) on the 13th of July,
and its been running 1 day, 12 hrs now ... there is hardly anything
running on this machine (10 jails), and vnode usage is:
debug.numvnodes: 336460 - debug.freevnodes: 5275 - debug.vnlru_nowhere: 0 -
vlruwt
One of my older servers (neptune), running kernels from Feb 13th of this
year, and with 81 jails running on it, is using up *significantly less*
vnodes (uptime: 1 day, 10 hours):
debug.numvnodes: 279710 - debug.freevnodes: 91442 - debug.vnlru_nowhere: 0 -
vlruwt
Now, compared to neptune, mercury isn't running anything special ...
several apache 1 processes, postfix, cyrus-imapd and that's it ...
neptune on the other hand, is running the full gambit ... aolserver, java,
apache 1 and 2, postfix, etc ...
So, I'm starting to think that the problem isn't "hardware related", but
the kernel itself ... the latest 4.11-STABLE kernel seems to have brought
in new vnode leakage, or ... vnlru isn't working as it should be to free
up vnodes ...
Looking at that process on mercury:
# ps aux | grep vnlru
root 7 0.0 0.0 0 0 ?? DL Wed11PM 0:00.65 (vnlru)
whereas on neptune:
# ps aux | grep vnlru
root 9 0.0 0.0 0 0 ?? DL Thu01AM 0:00.79 (vnlru)
so about the same about of CPU time being expended ... a bit more on the
more loaded server, but not a major amount ...
I'd like to try and debug this, but don't know where to start ... I
realize that 4.x isn't being pushed anymore, but there are alot of us that
haven't moved to 5.x yet (am working on that for our next server, but its
going to take me several months before I can convert all our existing
servers up) ...
I do have a serial console on this server, if that helps to debug things
...
I've heard that there was some work done on 5.x to clean up some of the
vnode leaks ... not sure if that is fact or just rumor ... but, if so,
would any of them be MFCable to 4.x?
Thanks ...
----
Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: [EMAIL PROTECTED] Yahoo!: yscrappy ICQ: 7615664
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
