Yes, we should avoid a basic discussion on performances. I can only talk about our experiences, we're also still running with some iSCSI Luns on ESX, but in comparison to NFS, I don't see many advantages. The "horrible" statement was leading to the performance of the software iscsi implementation of esx, and a little over the top. But if I compare the Microsoft iSCSI Initiator with the ESX initiator, the difference is noticeable, YMMV.
The biggest advantage of NFS is the flexibility, that you can increase/decrease the size of your datastore, just as you want. You don't have this flexibility with block access and therefore with iscsi.
We did some perf tests between iscsi and nfs and we didn't recognized any performance advantage of iscsi in comparison to nfs, so that we would say, it's OK to give up the flexibility of nfs and switch completely to iscsi. NFS was even a little faster that iscsi. We have no experiences with FCP and ESX, it was always a question between nfs and iscsi for us.
So just some experiences we've made, no general denigrating of iscsi.
I would be interested in the reason, why you have chosen iscsi instead of nfs. Just because of the license costs?
-----Original Message----- From: Milazzo Giacomo [mailto:G.Milazzo@sinergy.it] Sent: Tuesday, March 04, 2008 4:05 PM To: Buerger, Andreas; Nick Silkey; toasters@mathworks.com Subject: R: R: VMware - snap - backup
And I've to (re)correct you :-) NFS? Avoiding phylosophical discussion on performances, VMware itself states to use it just for ISO or templates... you perfectly know how much costs the NFS license! Terrible!!! iSCSI is free (bundle) and we've tested also on huge SATA disks...no issues.
Why do you said that iSCSI implementation is horrible? It's so easy to setup...
-----Messaggio originale----- Da: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] Per conto di Buerger, Andreas Inviato: martedì 4 marzo 2008 14.38 A: Nick Silkey; toasters@mathworks.com Oggetto: RE: R: VMware - snap - backup
I have to correct you :) We did some tests with vcb and iscsi, it works fine, but vcb in general was not very convenient. And the other thing is that the iscsi implementation in esx is horrible. Use NFS to earn more flexibility and an even better performance.
That's the experience we've made.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Nick Silkey Sent: Tuesday, March 04, 2008 1:17 PM To: toasters@mathworks.com Subject: Re: R: VMware - snap - backup
Milazzo Giacomo wrote:
As I told you in another mail your environment make me more persuaded that the best thing you could do is to use VCB.
VCB = VMWare Consolidated Backup?
AFAIK, it is not an option in an iSCSI environment[1] ... if this is not the case, do correct me as we are aggressively pursuing iSCSI on our 3020s as a prod means to store vmdks for ESX. :)
[1]: http://www.vmware.com/files/pdf/iSCSI_design_deploy.pdf