My Oracle Support Banner

Solaris 11 Guest on VMware ESXI Can Submit Only One Disk I/O at a Time (Doc ID 2238101.1)

Last updated on OCTOBER 05, 2022

Applies to:

Solaris x64/x86 Operating System - Version 11.2 and later
Information in this document applies to any platform.


Hypervisor (ESX 5.5U3) sees I/O from Solaris 11 guest arriving on its virtualized LSI Logic SAS scsi controller as synchronous I/O. Meaning that Solaris 11 only queues 1 disk I/O at a time.

Solaris 10 machines, using the same virtualized LSI Logic SAS scsi controller show multiply disk I/Os queued on these same HBA.

The end result is a disk I/O bottleneck with Solaris 11.

Solaris 11 is performing significantly worse in high disk I/O situations, as it appears to be a bottleneck not being able to send more than 1 outstanding I/O at a time.

Iostat shows the following output for c4 which is connected to local disk.

c4 is a virtual LSI HBA:


This is a new Solaris 11 installation. The issue only exists with Solaris 11.

So far, the customer was using Solaris 10 guest on its ESXi server. No such issue existed with Solaris 10.


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.