Andy,
I was in the same boat you are in trying to figure out which was better. I
originally started out with NFS being served up through a NetApp SAN and was
running 100+ virtual machines through it across 4 servers. The problem was
performance was terrible. It works ok if you are serving up a machine here or
there and all they do is run. However, if you are going to script out your
builds and have a 4 or more machines being built at once that is when you will
see the performance hit. Once the creation is completed performance will
usually go back to normal.
I did recently switch to iscsi in an ocfs2 format clustered on 2 servers for
testing and it is a lot better. However, there is a current bug with it tht
Novell is writing a patch for me on and I should hopefully have it today or
tomorrow. I also have 2 other servers that have their own iscsi volumes tied to
them. All in all I am extremely happy with the consistent performance I am
getting for the ISCSI volumes and highly recommend them.
Pros and cons:
NFS:
Extemely easy to manage. And if you SAN provider has de-dupe support the NFS
volumes de-dupe really good. But Performance is bad and will cause some thinning
in the hairline.
Iscsi:
Consistent reliable performance can be used as a cluster aware file system
depending how you format it out.
Doesn''t de-dupe nearly as well as NFS does and isn''t as easy
to manage or resize on the fly like NFS so you need to keep an eye on your
volumes and manage them a little more closely.
Hope this helps if you have further questions shoot me an email
joe.coleman@infinitecampus.com
Message: 5
Date: Mon, 1 Feb 2010 22:57:19 -0600
From: Andy Pace <APace@singlehop.com>
Subject: [Xen-users] iSCSI vs NFS
To: "xen-users@lists.xensource.com"
<xen-users@lists.xensource.com>
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Which is the easiest to manage with multiple (lets say hundreds) of xen
VM''s without sacrificing performance, and why?
What are the pro''s and cons to each? From my research, iSCSI seems the
way to go here, but all the SAN/NAS vendor''s I''ve spoken with
live and die *NFS*, which I''ve had some serious issues with in the past
in so far as scalability and performance...
Just thought i''d get an outside/un-biased (i hope!) opinion...
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On Tue, Feb 2, 2010 at 6:28 AM, Joseph Coleman < joe.coleman@infinitecampus.com> wrote:> Andy, > > I did recently switch to iscsi in an ocfs2 format clustered on 2 servers > for testing and it is a lot better. However, there is a current bug with it > tht Novell is writing a patch for me on and I should hopefully have it today > or tomorrow. I also have 2 other servers that have their own iscsi volumes > tied to them. All in all I am extremely happy with the consistent > performance I am getting for the ISCSI volumes and highly recommend them. > > Pros and cons: > > NFS: > > Extemely easy to manage. And if you SAN provider has de-dupe support the > NFS volumes de-dupe really good. But Performance is bad and will cause some > thinning in the hairline. > > Iscsi: > > Consistent reliable performance can be used as a cluster aware file system > depending how you format it out. > > Doesn’t de-dupe nearly as well as NFS does and isn’t as easy to manage or > resize on the fly like NFS so you need to keep an eye on your volumes and > manage them a little more closely. > > Hope this helps if you have further questions shoot me an email > joe.coleman@infinitecampus.com >Joe, The iSCSI with OCFS is faster than NFS? Where do you suppose the speed increase is coming from? It would seem that you have a lot more layers than before and the addition a clusterfs. I haven''t seen any recent speed tests on cluster fses but about 2 years ago another company I contracted with canceled their Xen deployment because the performance hit from GFS2 crippled their servers. It was somewhere in the order of 30% of the speed of native ext3 on local storage. I left the project after that so I''m not sure if they re-evaluated later. As I''ve mentioned in another thread I''m going to be doing extensive testing on these various methods. Do you have any words of advice on your testing methods? Grant McWilliams Some people, when confronted with a problem, think "I know, I''ll use Windows." Now they have two problems. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users