Subject: Re: [PATCH 00/29] Swap over NFS -v15

From: Peter Zijlstra <[email-masked]>
Date: Thu, 20 Dec 2007 09:00:04 +0100

On Wed, 2007-12-19 at 17:22 -0500, Bill Davidsen wrote:
> Peter Zijlstra wrote:
> > Hi,
> > 
> > Another posting of the full swap over NFS series. 
> > 
> > Andrew/Linus, could we start thinking of sticking this in -mm?
> > 
> 
> Two questions:
> 1 - what is the memory use impact on the system which don't do swap over 
> NFS, such as embedded systems, and

It should have little to no impact if not used.

> 2 - what is the advantage of this code over the two existing network 
> swap approaches, 

> swapping to NFS mounted file and 

This is not actually possible with a recent kernel, current swapfile
support requires a blockdevice.

> swap to NBD device?

> I've used the NFS file when a program was running out of memory and that 
> seemed to work, people in UNYUUG have reported that the nbd swap works, 
> so what's better here?

swap over NBD works sometimes, its rather easy to deadlock, and its
impossible to recover from a broken connection.