We have performance problems since upgrading to new filer heads running at 4Gb. Our old heads ran at 2Gb.
- HP c-Class c7000 blade enclosure
- 10 x HP ProLiant BL465c G5/G6/G7 blades running VMware ESX 4.0 U2
- Each blade has 2 x QLogic QMH2462 HBAs. HBAs running latest firmware as per HP's firmware update DVD
- 2 x NetApp FAS3140 heads running ONTAP 8.0.1P3 7-Mode, Active/Active
- NetApp Virtual Storage Console installed and recommended settings implemented on all ESX hosts
- 2 x Brocade 200E and 2 x 300 FC switches, running firmware 6.2.2e
- Setting the FC switch port for an ESX blade to 4Gb causes very high disk latency (as seen within VMware) and rapidly accumulating errors on the FC switch
- Change the port speed to 2Gb and all the problems disappear
- Rebuilding a blade to Windows 2008 R2 has exactly the same issues (works at 2Gb, but errors at 4Gb)
- Physical Dell Windows servers running Exchange at 4Gb on the same FC switches do not have problems. These servers are not in our c-Class enclosure and they have different HBAs.
- We only started getting this problem at about the time when the NetApp filer heads were changed and set to 4Gb. The old filer heads ran at 2Gb. Until the filer heads were changed, all the ESX blades could run with their FC switch ports set to 4Gb with no problems.
So, we think the problem is either the QLogic HBAs, or an issue with the c-Class enclosure, or some combination of these. We are going to borrow an Emulex HBA for the c-Class blades to test with – this will tell us if it’s an issue with the QLogic HBAs.
Has anyone else seen a similar issue before? Any ideas on what to test next?