[Beowulf] disabling swap on cluster nodes?

[Andrew Shewmaker]

On Fri, Feb 6, 2015 at 8:57 PM, Alan Louis Scheinine <
alscheinine at tuffmail.us> wrote:

> Only problem I've seen is that if a user allocates too much memory,
> OOM killer can kill maintenance processes such as a scheduler daemon.


I've seen that too. Even when the OOM killer targets the right processes, I
remember having issues that only went away with a reboot.

With no swap, then I found tuning the overcommit settings to be important
to making things stable. It also depends on the kernel version ... older
kernels had free page scanning algorithms that scaled poorly. Much better
now.

If you want to squeeze the most useful memory out of a system that you can
while remaining stable, then I recommend having at least a little swap.

-- 
Andrew Shewmaker
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