Re: more ram/swap on leisner, please?
On Wed, 2008-01-02 at 21:32 +0100, Lennert Buytenhek wrote:
> On Wed, Jan 02, 2008 at 02:17:46PM -0600, Bill Gatliff wrote:
>
> > >>Ok, I've set up a 5GB swap over NBD. If the system reboots, it won't
> > >>automagically reattach it.
> > >>
> > >>The kernel is NOT running the nbd swap patch, so I don't know if the
> > >>system will deadlock under stress, or not...
> > >
> > >It most likely will...
> >
> > Older kernels definitely would. But the mailing lists aren't
> > so clear about the current state of things,
>
> The issue of network swap deadlocking has not been fixed so far.
>
>
> > and I can't seem to find the patches either...
>
> Peter Zijlstra and Daniel Phillips have been posting patches to fix
> the underlying issue, but those have not been merged yet, as far as
> I know.
>From http://nbd.sourceforge.net/
Current state: It currently works. Network block device seems to be
pretty stable. It was originaly thought that it is impossible to swap
over TCP. This turned out not to be true, though the patch required to
make it safe has not been forward-ported to any reasonably recent
kernel.
If you want swapping to work, first make nbd working. (You'll have to
mkswap on server; mkswap tries to fsync which will fail.) Now, you have
a version which mostly works. Ask me for kreclaimd if you see deadlocks.
David
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