Re: mysql frequently crash on 6.2
Jeremy Chadwick <koitsu <at> FreeBSD.org>
2007-05-01 02:07:21 GMT
On Tue, May 01, 2007 at 09:11:28AM +0800, Ken Chen wrote:
> After moving the database from Linux 2.4 to FreeBSD 6.2, the mysqld crash
> very frequently! I think the problem is on FreeBSD when myusql is heaving
> I have another same machine with lower loading, the mysql is stable.
I can confirm this problem. Normally sig11 is an indication that you
have hardware-related problems, but in this particular case (at least in
my experience), it can also be caused by some lack-of loader.conf
tunables permitting mysqld to allocate the amount of memory you're
claiming in my.cnf.
My loader.conf comments may not be absolutely correct (folks who know
the innards of the VM will probably correct me in my claims), but I can
confirm that increasing kern.maxdsiz/dfldsiz/maxssiz relieved all
bizarre sig11 issues we were seeing.
I'll use our production SQL server as an example:
# dmesg | grep ' memory'
real memory = 1073676288 (1023 MB)
avail memory = 1041801216 (993 MB)
# top -d 1 -U mysql
Mem: 207M Active, 598M Inact, 138M Wired, 42M Cache, 111M Buf, 11M Free
Swap: 8192M Total, 16K Used, 8192M Free
PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMMAND
914 mysql 6 20 0 754M 173M kserel 31:54 0.00% mysqld