Hello!
> Thank you very much. I didn't know that. I set my shmmax to 4000000000 but you're right, we will see to use a 64 bits
system;)
My experience with this amount of memory in Debian Etch works much better in a 64bit environment. BIGMEM kernel handles
pagesin a way that the performance is a bit degraded.
> I wanted to give to postgres 4GB. So I tryied to set shmmax to 4Go :
>
> sysctl kernel.shmmax=4294967296
>
>
> But it doesn't work : if I launch after this modification this command :
>
> sysctl kernel.shmmax
>
> it gives me this response :
>
> kernel.shmmax = 0
>
> Why? Is there a limit to shmmax?
I don't see limits in shmmax but the command you're typing is wrong.
To set a value you need to do:
sysctl -w kernel.shmmax=VALUE
or alternatively:
cat VALUE > /proc/sys/kernel/shmmax
Don't forget to write in your /etc/sysctl.conf:
kernel.shmmax=VALUE
Without spaces. This will make your setting persistent.
Regards
Flavio