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.
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