Julio pretty well summed things up.
Think of iSCSI as iSAN. It's still a SAN setup and the blocks move over the very same SCSI protocol. Whether it's SCSI over FCP or SCSI over IP makes no real difference. With that in mind, you should treat your iSAN setups with the same consideration as SAN. Dedicated links, VLANs, etc.
A TOE card should only be deployed once you know you need one. Start with a standard host NIC and watch your host's CPU. If it's being driven to capacity, a TOE or iSCSI HBA will help. If it's not, you're really just wasting money.
-Charles
-----Original Message----- From: Julio Calderon [mailto:jcalderon@agami.com] Sent: Tuesday, November 21, 2006 9:21 PM To: Raj Patel; toasters@mathworks.com Subject: RE: iSCSI SAN Queries Greetings, I've had first hand experience with Netapp 270s / iSCSI on couple of windows host. (past life) Nutshell: SLOW, don't try exchange on it, it kept timing out on me. I've also seen a large client have issues with Lotus notes when using Gfilers 980c and HDS as the backend storage. (this was a poor configuration issue, too many LUNs over a 1 gig connection) I've also tried it for another purposes and I lost my LUN a few times. The only way of getting it back then was by restarting the client! not a fun thing to do when you are running multiple apps on the same server. Suggestion would be, directly attach application servers via GigE across to your iSCSI device. If direct connecting your app servers is not realistic. use VLANs to segregate traffic, dedicate iSCSI traffic to a set of bonded ports. Start slow, make sure that the number of LUNs being provisioned to the app servers are provisioned in a control manner. (meaning, see how your application behaves in a controlled environment before doing any big role out) Monitor performance, use a testing tool (iozone) to see how much performance you would gain or loose from moving away from current solution. Also, consider the advantages and disadvantages an iSCSI solution would bring your environment. (replication, HA, speed, easy of management, backup, etc) TOE ? I think that the purpose of having iSCSI in your environment is to lower the investment of FC (SAN) solution by leveraging your current network infrastructure and current staff expertise so, if you start purchasing the TOE cards, you will in fact start cutting into the savings a properly architected and managed IP SAN (iscsi) solution would offer your company. I have not had the opportunity to try a TOE card nor have I needed it to yet since I am able to reach almost wire speeds on GigE at the moment. Can not comment on the HDS and EMC solutions but I can't believe they would be better than what Netapp has to offer since their main business is in the FC world. Hope this helps guide you!
Best Regards, Julio Calderon West Region - Systems Engineer
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From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Raj Patel Sent: Tuesday, November 21, 2006 11:40 AM To: toasters@mathworks.com Subject: iSCSI SAN Queries Hi, We're in the preliminary scoping phase for a low/mid-range iSCSI SAN solution. I was wondering if anyone had any positive or negative real-world experiences with - NetApp 270c HDS AMS200 EMC CX320 At the moment the NetApp is the most familiar to me as I have used one of their NAS boxes before and the simulator provides a pretty good indication of how it works. However the iSCSI seems a bit of a 'bolt-on' and its not clear if it will handle tiered storage as well as the other vendors (then again does it matter?). The HDS & EMC are unknown quantities (other than what I can glean from the web). Any feedback concerning ease of use, expansion, licensing, snapshot mechanism (the EMC seems clunky from their literature but I don't know if that's the case in operation). Also does anyone have any iSCSI 'gotchas' ? Is a TOE one of those 'nice to have but not really necessary' things on a modern server or should it be factored into the solution ? Cheers, Raj.