RE: [cobalt-security] kernel: VM: do_try_to_free_pages failed for ... ?

[Graeme Fowler <graeme.fowler@xxxxxxxxxxxxxx>]

Michael wrote:
> Jun 17 15:21:55 admin kernel:
>	VM: do_try_to_free_pages failed for mysqld... 
>
> Jun 22 09:14:23 admin kernel:
>	VM: do_try_to_free_pages failed for emumail.cgi...
>
> Any ideas what this "do_try_to_free_pages" error is about
> and how to prevent it?

Not really a security-related question, however I'll answer it here anyway.

As the syslog states, it's a kernel reported error. Basically the machine is
so badly out of real RAM at that point that the kernel has started 'swapping
agressively' but cannot free any more VM (virtual memory) pages for
processes to start, hence the "do_try_to_free_pages failed" error. That
means it's out of swap memory too.

There's two issues here:
1. your kernel has possibly flaky VM handling, but this is doubtful.
2. something (scripts, sites, email) is hammering the system. This is more
probable.

There's also two solutions:
1. Make sure your kernel is a recent as possible.
2. Add more RAM or make your swap partition larger. The former is the best
idea, the latter is a bodge and may not work long-term.

Also, check the scripts you have running on your system. One of them may be
looping.

Graeme
-- 
Graeme Fowler
System Administrator
Host Europe Group PLC