On Fri, Dec 9, 2011 at 10:27 AM, Alan McKay alan.mckay@gmail.com wrote:
Now my questions : We are not using iSCIS yet at work but I see a few places where it would be useful e.g. a number of heavy-use NFS mounts (from my ZFS appliance) that I believe would be slightly more efficient if I converted them to iSCSI. I also want to introduce some virtual machines which I think would work out best if I created iSCSI drives for them back on my Oracle/Sun ZFS appliance.
This doesn't directly apply, but this nfs appliance vendor wants you to think that nfs isn't as bad as you might think: http://www.bluearc.com/bluearc-resources/downloads/analyst-reports/BlueArc-A... Overcommitting for de-dup/compression might be harder with iscsi - resizing filesystems would be a lot harder.
I mentioned iSCSI to the guy whose work I have taken over here so that he can concentrate on his real job, and when I mentioned that we should have a separate switch so that all iSCSI traffic is on it's own switch, he balked and said something like "it is a switched network, it should not matter".
Is it a single switch? Otherwise you share the bandwidth on the trunk connections.
But that does not sit right with me - the little bit I've read about iSCSI in the past always stresses that you should have it on its own network.
So 2 questions :
- how important is it to have it on its own network?
- is it OK to use an unmanaged switch (as long as it is Gigabit), or are
there some features of a managed switch that are desirable/required with iSCSI?
I've seen recommendations to use jumbo frames for iscsi - and if you do that, everything on that subnet needs to be configured for them.