HP StorageWorks SAN Virtualization Services Platform administrator guide (5697-0204, January 2010)

2. Select the Disk configuration option and scroll down to the Disk,DiskMaxIOSize option, and
change the value in the field to 1024.
3. Apply the changes and reboot the ESX server.
Using Windows Guests on VMware with VSS
The DPM VSS hardware provider installed on a Windows Virtual machine does pass the request to
create a VSS snapshot properly to the VSM, and the VSM does respond properly to this request by
creating the PIT and the snapshot and assigning it back. However, the snapshot is assigned to the
ESX server and not directly to the virtual machine (the VSM is not aware of the virtual machine HBA
and therefore cannot assign it to the virtual machine HBA). The DPM VSS hardware provider on the
virtual machine waits about 8 minutes for the snapshots, times out, and finally fails.
The manual workaround is to perform the following steps on the ESX server side (using vCenter):
1. Discover the snapshot as a “Disk.” (Configuration tab, Storage Adapter link, and then click
Rescan.)
2. From the Virtual Machine side, add the discovered snapshot disk to the virtual machine. (Virtual
Machine Edit settings, Add Hard disk )
3. Initiate a rescan on the Windows virtual machine to discover the new added disk/snapshot.
Installing multipath applications
An active-passive multipath driver is required on any server that has access to the HP StorageWorks
SAN Virtualization Services Platform. Multipath information for Linux and Windows is available at
Adding devices to the domain36