High latency in I/O storage after upgrade to ESXi 5.X

[vRawl]

Since I upgraded from ESXi 4.1 up3 to ESXi 5.X when copy a large file  from locals units of a virtual machine or between differents virtual machines across network, the latency of target datastore grows considerably and the general performance is very poor.

The storage device is a EMC CX4 440 with last available flare. For ESXi 5.X VAAI is not supported and I turned off. With this modification the issue persist.

The datastores managed by the storage controller owner of target datastore too are affected. However RDM luns owned by this storage controller don't have degraded performance, only VMFS volumes. VMFS version is 5 in all datastores.

¿Any idea?

[elgreco81]

Hi,

As an idea...I could guess that maye you upgraded the VMFS3 to VMFS5 instead of creating the partition from scratch. This document written by Cormac Hogan explains the differences.

http://www.vmware.com/files/pdf/techpaper/VMFS-5_Upgrade_Considerations.pdf

Sadly, I don't see how it could explain why your RDMs don't have a performance problem.

If your storage is iSCSI, are jumbo frames enbaled? Did you checked esxtop to try to see any bottleneck in there?

Regards,

elgreco81

[vRawl]

All datastores are newly created and has version 5 of VMFS. The datastores are connected by FC.