[Lustre-discuss] Swap over lustre

2011-08-17 Thread John Hanks
Hi, I've been trying to get swap on lustre to work with not much success using blockdev_attach and the resulting lloop0 device and using losetup and the resulting loop device. This thread (http://www.mail-archive.com/lustre-discuss@lists.lustre.org/msg00856.html) claims that it works, but in all m

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread Joe Landman
On 08/17/2011 10:43 PM, John Hanks wrote: > Hi, > > I've been trying to get swap on lustre to work with not much success > using blockdev_attach and the resulting lloop0 device and using > losetup and the resulting loop device. This thread > (http://www.mail-archive.com/lustre-discuss@lists.lustre.

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread David Dillow
On Wed, 2011-08-17 at 22:57 -0400, Joe Landman wrote: > The lustre client (and most NFS or even network block devices) all do > memory allocation of buffers ... which is anathema to migrating pages > out to disk. You can easily wind up in a "death spiral" race condition > (and it sounds like yo

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread John Hanks
On Wed, Aug 17, 2011 at 8:57 PM, Joe Landman wrote: > On 08/17/2011 10:43 PM, John Hanks wrote: > As a rule of thumb, you should try to keep the path to swap as simple as > possible.  No memory/buffer allocations on the way to a paging event if > you can possibly do this. I do have a long path th

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread Kevin Van Maren
John Hanks wrote: > FWIW, mounting a file on lustre via loopback to provide a local > scratch filesystem works really well. > Mostly, but you probably need a kernel patch. See https://bugzilla.lustre.org/show_bug.cgi?id=22004 Kevin ___ Lustre-disc

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread Joe Landman
On 08/17/2011 11:42 PM, David Dillow wrote: > On Wed, 2011-08-17 at 22:57 -0400, Joe Landman wrote: >> The lustre client (and most NFS or even network block devices) all do >> memory allocation of buffers ... which is anathema to migrating pages >> out to disk. You can easily wind up in a "death s

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread Andreas Dilger
On 2011-08-17, at 8:43 PM, John Hanks wrote: > I've been trying to get swap on lustre to work with not much success > using blockdev_attach and the resulting lloop0 device and using > losetup and the resulting loop device. This thread > (http://www.mail-archive.com/lustre-discuss@lists.lustre.org/m

Re: [Lustre-discuss] Swap over lustre

2011-08-17 Thread Temple Jason
Jason -Original Message- From: lustre-discuss-boun...@lists.lustre.org [mailto:lustre-discuss-boun...@lists.lustre.org] On Behalf Of John Hanks Sent: giovedì, 18. agosto 2011 05:55 To: land...@scalableinformatics.com Cc: lustre-discuss@lists.lustre.org Subject: Re: [Lustre-discuss] Swap over l

Re: [Lustre-discuss] Swap over lustre

2011-08-18 Thread John Hanks
On Thu, Aug 18, 2011 at 12:36 AM, Temple Jason wrote: > Hello, > > I experimented with swap on lustre in as many ways as possible (without > touching the code), and had the shortest path possible to no avail.  The code > is not able to handle it at all, and the system always hung. > > Without s

Re: [Lustre-discuss] Swap over lustre

2011-08-18 Thread Andreas Dilger
c: lustre-discuss@lists.lustre.org > Subject: Re: [Lustre-discuss] Swap over lustre > > On Wed, Aug 17, 2011 at 8:57 PM, Joe Landman > wrote: >> On 08/17/2011 10:43 PM, John Hanks wrote: >> As a rule of thumb, you should try to keep the path to swap as simple as >>

Re: [Lustre-discuss] Swap over lustre

2011-08-18 Thread Phil Sharfstein
on behalf of John Hanks Sent: Thu 8/18/2011 7:30 AM To: Temple Jason Cc: lustre-discuss@lists.lustre.org Subject: Re: [Lustre-discuss] Swap over lustre On Thu, Aug 18, 2011 at 12:36 AM, Temple Jason wrote: > Hello, > > I experimented with swap on lustre in as many ways as possible