[CentOS] Good value for /proc/sys/vm/min_free_kbytes

Fri Dec 8 21:31:51 UTC 2006
Aleksandar Milivojevic <alex at milivojevic.org>

Quoting Martin Knoblauch <spamtrap at knobisoft.de>:

> Hi,
>
>  what would be a good value for
>
> /proc/sys/vm/min_free_kbytes
>
>  on a Dual-CPU EM64T System with 8 GB of memory. Kernel is
> 2.6.9-42.0.3.ELsmp. I know that the default might be a bit low.
> Unfortunatelly the documentation is a bit weak in this area.
>
>  We are experiencing responsiveness problems (and higher than expected
> load) when the system is under combined memory+network+disk-IO stress.

Actually, under similar load, I experinced ext3 file system corruption  
(RHEL4/CentOS4 kernels).  In my case it was memory+cpu+network.  All I  
was doing was running a simple Perl script.  For details check out:

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=202955

Appernetly, Red Hat considers increasing default value for  
min_free_kbytes in update 5.

Increasing it to 8192 seems to do good job in preventing Linux kernel  
to deny memory to itself (and destroying my valuable data).  Well, at  
least in my case.