[CentOS] iSCSI best practices

Sat Dec 10 19:05:42 UTC 2011
James A. Peltier <jpeltier at sfu.ca>

----- Original Message -----
| On Dec 10, 2011, at 1:49 PM, "James A. Peltier" <jpeltier at sfu.ca>
| wrote:
| > Jumbo frames is really the important thing when it comes to iSCSI.
| > Having 9000 byte packets verses 1500 byte packets will dramatically
| > increase your performance per interrupt. Most cheaper unmanaged
| > switches cannot do this.
| I want to break the myth here, jumbo frames are really only important
| for 10Gbe+. On 1Gbe (or slow CPUs) they actually slow sequential
| throughput due to the time to process each packet on 1Gbe and how that
| in turn slows down packet interleaving and thus total throughput.
| -Ross

On cheap network switches...  When you've got a switch that has 1 or more 10Gb uplinks and the rest of the switch is Gb, I doubt this is an issue, but I will agree that on *some* switches it may be detrimental to performance.

James A. Peltier
Manager, IT Services - Research Computing Group
Simon Fraser University - Burnaby Campus
Phone   : 778-782-6573
Fax     : 778-782-3045
E-Mail  : jpeltier at sfu.ca
Website : http://www.sfu.ca/itservices
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