VMware Cloud Community

Write Latency issue on VMs and Datatstore

I have multiple VMs hosted on a HA enabled cluster.

While investing the Latency issue on storage I found few VMs hosted on iscsi datastore generating the 500iops with 512kb of size. 

We already enabled the jumbo frame and also setup the port binding on iscsi adapter.

I can see there is a setting to change the max iscsi io size in esxi to 512 which is by default is 128.


What's your option will it improve the storage performance?

esxcli system settings advanced list -o /ISCSI/MaxIoSizeKB
   Path: /ISCSI/MaxIoSizeKB
   Type: integer
   Int Value: 512
   Default Int Value: 128
   Min Value: 128
   Max Value: 512
   String Value:
   Default String Value:
   Valid Characters:
   Description: Maximum Software iSCSI I/O size (in KB) (REQUIRES REBOOT!)



0 Kudos
1 Reply

It could, have you checked though what kind of latency you are seeing and where it is coming from? Normally when things like these need to be tweaked it is done as a result of a recommendation from the storage vendor.

0 Kudos