Is iSCSI better for performance for SQL Server?

[rottengeek35]

This was asked a few years ago, and someone performed actual tests.  I'm wondering if Nimble has some benchmarks you can provide regarding the suggested in-guest iSCSI attached vs. a VMDK w/paravirtual SCSI driver? What about other scenarios?

If I'm not using Nimble for replication, is there a reason to use iSCSI?

Do you have performance numbers show me what to expect?  Multiple tests have been done on other SANs with varying setups and generally iSCSI doesn't win out.

My particular environment is VMware 5.5, SQL Server 2014 (mostly) and Nimble 3.7.

[Nick_Dyer · Accepted solution]

I haven't seen anything like this for a few years - mostly because performance between in-guest, VMFS and now VVols are pretty much even. The choice now becomes reliant on the way you wish to manage, snapshot and restore your datasets.

[rottengeek35]

So my plan is to try replacing the iSCSI drives with VMDKs attached with paravirtual SCSI drivers on one of our high I/O test SQL Servers and see if there is any change.  Since these would be dedicated to SQL, would I still choose the SQL Performance plan?  I'm just replacing Data, Log and tempdb LUNS, moving corresponding files over.