Greetings and salutations,
We have deployed, quite successfully,
Netapp 3020 with iSCSI for all our Exchange and SQL servers. This solution has
been in prod for more than a year now and the issues that we have seen are not directly
related to iSCSI. Of course, we did put in place some safe guards that we believe
has made the whole solution more reliable like:
-
Run
complete separate network for our iSCSI traffic.
-
TOE
cards for our heavy-duty servers.
-
Overcapacity
on our filer heads.
We did this since our iSCSI decision had
nothing to do with cost (which at the time of the RFP FC was still
significantly more expensive than iSCSI) but with our desire to keep our
installation simple and not having to bring a new protocol/environment (FC)
under our management. iSCSI has proven to be as fast, reliable and cost
effective as we expected it without the steep learning curve of FC. Here are a
few findings:
-
TOE: On
our lab we saw a 7%to 12% CPU savings by using them therefore we did not
justify them for performance reasons but we ended up using them for SAN booting
requirements.
-
iSCSI Performance:
on our lab/RPF we noticed better performance out of FC under heavy load
conditions. Under our expected loads (low to average), we did not noticed any
significance performance gains on FC over iSCSI.
-
iSCSI
Implementation: We also noticed that a year ago iSCSI looked like an “add-on”
to most of the SAN vendors we spoke with. We selected Netapp for their
simplicity and easy of management and both have been proven to be true.
Regards,
SPV
From:
owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Julio Calderon
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 |
|
|
agami |
Work: 408.349.0414 |
|
|
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.