Paravirtual SCSI (PVSCSI) controllers are high performance storage controllers that can result in greater throughput and lower CPU use. PVSCSI controllers are best suited for high-performance storage environments.
official testing result stated that
"The test results show that PVSCSI is better than LSI Logic, except under one condition--the virtual machine is performing less than 2,000 IOPS and issuing greater than 4 outstanding I/Os. This issue is fixed in vSphere 4.1, so that the PVSCSI virtual adapter can be used with good performance, even under this condition.
The CPU utilization difference between LSI and PVSCSI at hundreds of IOPS is insignificant. But at larger numbers of IOPS, PVSCSI can save a lot of CPU cycles."
In Aug 26, 2011 ,published Achieving a Million I/O Operations per Second from a Single VMware vSphere 5.0 Host
Results obtained from performance testing done at EMC lab show that:
- A single vSphere 5 host is capable of supporting a million+ I/O operations per second.
- 300,000 I/O operations per second can be achieved from a single virtual machine.
- I/O throughput (bandwidth consumption) scales almost linearly as the request size of an I/O operation increases.
- I/O operations on vSphere 5 systems with Paravirtual SCSI (PVSCSI) controllers use less CPU cycles than those with LSI Logic SAS virtual SCSI controllers.
Limitations are:
- Hot add or remove requires a bus rescan from within the guest operating system.
- Disks on PVSCSI controllers might not experience performance gains if they have snapshots or if memory on the ESXi host is over committed.
- If you upgrade your Linux virtual machine to an unsupported kernel, you might not be able to access data on the disks attached to a PVSCSI controller. To regain access to such disks, you can run vmware-config-tools.pl with the kernel-version parameter to regain access.
- MSCS clusters are not supported.
- PVSCSI controllers do not support boot disks, the disk that contains the system software, on Red Hat Linux 5 virtual machines. Attach the boot disk to the virtual machine by using any of the other supported controller types.
support matrix for use of PVSCSI for data disks and boot disks
| Guest operating system | Data Disk | Boot Disk |
| Windows Server 2012 (64 bit only) | ESXi 5.0 Update 1, ESXi 5.1 | ESXi 5.0 Update 1, ESXi 5.1 |
| Windows Server 2008 R2 (64 bit only) | ESX/ESXi 4.0 Update 1, ESX/ESXi 4.1, ESXi 5.x | ESX/ESXi 4.0 Update 1, ESX/ESXi 4.1, ESXi 5.x |
Windows Server 2008 (32 and 64 bit)
|
ESX/ESXi 4.x, ESXi 5.x
|
ESX/ESXi 4.0 Update 1, ESX/ESXi 4.1, ESXi 5.x
|
Windows Server 2003 (32 and 64 bit)
|
ESX/ESXi 4.x, ESXi 5.x
|
ESX/ESXi 4.x, ESXi 5.x
|
| Windows 7 (32 and 64 bit) | ESX/ESXi 4.1, ESXi 5.x | ESX/ESXi 4.1, ESXi 5.x |
| Windows Vista (32 and 64 bit) | ESX/ESXi 4.1, ESXi 5.x | ESX/ESXi 4.1, ESXi 5.x |
| Windows XP (32 and 64 bit) | ESX/ESXi 4.1, ESXi 5.x | ESX/ESXi 4.1, ESXi 5.x |
Red Hat Enterprise Linux (RHEL) 5 (32 and 64 bit) and all update releases
|
ESX/ESXi 4.x, ESXi 5.x
|
Not Supported
|
RHEL 6 (32 and 64 bit)
|
ESX/ESXi 4.0 Update 2, ESX/ESXi 4.1, ESXi 5.x
|
ESX/ESXi 4.0 Update 2, ESX/ESXi 4.1, ESXi 5.x
|
SUSE Linux Enterprise 11 SP1(32 and 64 bit) and later releases
|
ESX/ESXi 4.0 Update 2, ESX/ESXi 4.1, ESXi 5.x
|
ESX/ESXi 4.0 Update 2, ESX/ESXi 4.1, ESXi 5.x
|
Ubuntu 10.04 (32 and 64 bit) and later releases
|
ESX/ESXi 4.0 Update 2, ESX/ESXi 4.1, ESXi 5.x
|
ESX/ESXi 4.0 Update 2, ESX/ESXi 4.1, ESXi 5.x
|
Distros using Linux version 2.6.33 or later and that include the vmw_pvscsi driver
|
ESX/ESXi 4.1, ESXi 5.x
|
ESX/ESXi 4.1, ESXi 5.x
|
ref:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1010398
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