> The theshold for using PAE is actually far lower than 4GB. 4GB is the
> total memory address space -- split that in half for 2GB for userspace,
> 2GB for kernel. The OS cache resides in kernel space -- after you take
> alway the memory allocation for devices, you're left with a window of
> roughly 900MB.
I set shammax =
[root(at)data3 /]# cat < /proc/sys/kernel/shmmax
[root(at)data3 /]# cat < /proc/sys/kernel/shmall
Is that ok for 4 Gb. mechine?
> Since the optimal state is to allocate a small amount of memory to
> Postgres and leave a huge chunk to the OS cache, this means you are
> already hitting the PAE penalty at 1.5GB of memory.
How could I chang this hitting?
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