Greetings,
I run my own email server for some domains I administer, on a centos
vps server with a very small number of users.

The only services are smtp, imap/pop, webmail

Everything was running without problems until this morning. I left
home for 1/2 hours, and when I came back everything had become about
100x slower (seriously!). The services were/are still all up and
running, but practically unusable (even running mutt in my ssh session
is almost frozen).

I have not changed/updated anything in the last 1/2 weeks. I have
already done a few checks with the VPS provider, and it looks like:

network & hardware are OK

there seem to be no strange processes running. I didn't manage to save
the output of "top", but it didn't show anything that (AFAICT, of
course) should not be there on an email server

however, there is something that is using "much more memory than
normal" (see the comment below from the hosting sysadmin after he
checked user_beancounters). Initially we thought it was apache, but
even switching it off didn't change anything. What now?

Any help to understand what the heck happened, and find out what
exactly _started_ to cause this problem is very welcome!

TIA,
Marco



root@vps [/etc/sysconfig]# cat /proc/user_beancounters
Version: 2.5
uid resource held maxheld
barrier limit failcnt
712: kmemsize 17208298 162267136
2147483646 2147483646 0
lockedpages 0 8
999999 999999 0
privvmpages 64694 262143
262144 262144 40
shmpages 14 2366
131072 131072 0
dummy 0 0
0 0 0
numproc 63 237
999999 999999 0
physpages 79977 262204
0 262144 0
vmguarpages 0 0
131072 2147483647 0
oomguarpages 30261 44087
131072 2147483647 0
numtcpsock 31 243
7999992 7999992 0
numflock 9 20
999999 999999 0
numpty 1 1
500000 500000 0
numsiginfo 0 27
999999 999999 0
tcpsndbuf 545000 7915960
214748160 396774400 0
tcprcvbuf 507904 3981312
214748160 396774400 0
othersockbuf 21832 1229736
214748160 396774400 0
dgramrcvbuf 0 118400
214748160 396774400 0
numothersock 56 356
7999992 7999992 0
dcachesize 10775271 154640329
2147483646 2147483646 0
numfile 772 1155
23999976 23999976 0
dummy 0 0
0 0 0
dummy 0 0
0 0 0
dummy 0 0
0 0 0
numiptent 57 57
999999 999999 0


As you can see, there are some fails for the privvmpages. This means
your VPS tried to use more RAM than what is available (e.g. more than
1GB RAM). If you are only running some basic mail services on your
VPS, that's definitely not normal and you should investigate that
accordingly. We have fully checked everything for hardware and network
problems and everything is working flawlessly. In combination with the
RAM shortage errors, it is safe to conclude that there's something
within your VPS itself that's malfunctioning.
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos