Hi,
We have switched to kernel 2.6.11.6 from kernel 2.4.26 ... since this date we have many troubles with PostgreSQL and most of them seems to be memory troubles.
As far as we can see, kernel kills the postmaster process when it begins to use swap. You can see the output from dmesg at the bottom of the message. The first thing I am not sure to understand is that the kernel should kill processes to reallocate memory only when physical memory and swap memory are exhausted, shouldn't it ?
Second thing: it seems to be related to our kernel switch as it did not happen before that.
This can occur when queries / a vacuum require too much memory to run.
I have configured my kernel with these options:
# shared mem kernel.shmmax= 641604096
# semaphore
kernel.sem = 250 32000 100 400
fs.file-max=65536
# overcommit
vm.overcommit_memory=2
Does anyone can explain me why I have this problem and how to resolve it ?
This server is a dedicated PostgreSQL server with 4Gb of RAM.
You might want to try vm.overcommit_memory=1. You don't appear to be the only one suffering from an over-zealous oom-killer.
http://www.ussg.iu.edu/hypermail/linux/kernel/0501.2/1295.html http://www.linuxquestions.org/questions/history/291119
-- Richard Huxton Archonet Ltd
---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
