VMWare ESXi MaxIOSize recommendation?

Posted in 2015

Lyubomir Grigorov — Tue, 08 Sep 2015 13:31:06 — source: IIUG Forums & Mailing Lists

Hi all, We have several Informix 11.70.FC8GE instances with default block size (4K), running on VMs with Windows 2008 Server, where we are undergoing an performance problem related to high read/write latency between DB servers and SAN. As part of the steps to remedy this, the VMWare admin advises that we need to change MaxIOSize parameter from VMware side. Can somebody please provide recommendations how it is best to calculate the value of this parameter? Thanks in advance! Regards, --001a113a7caa9244a4051f3c60ca

↪ replying to Lyubomir Grigorov

KARL OLIVER — Tue, 15 Sep 2015 02:37:06 — source: IIUG Forums & Mailing Lists

I think there is a bit more to it than that. Since you are running a vm you really don't know when record is written, You also don't know what else is running on physical machine your vm is on. Also I don't think windows server has write cache enabled - certainly doesn't on our windows servers. You want good response best not run on vm however people have probably already told you that, probably doesn't help you I suppose Karl