Setup Guide

34 Best Practices
Adjusting SCSI Timeouts for the PowerVault MD3000 RAID Enclosure
If the XenServer host is connected to the PowerVault MD3000 RAID
enclosure, you can adjust the SCSI time-out of the Windows VMs residing on
the SR resident on the PowerVault MD3000 RAID enclosure by changing the
registry settings. Follow the steps below:
1
Navigate to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\dis
k\TimeOutValue
.
2 Create the value if it is not present. Set this value to 200 .
NOTE: Do not modify the SCSI timeout in the paravirtualized Linux VMs as the
VM virtual disks are not presented as SCSI disks.
Adjusting SCSI Timeouts for the PowerVault MD3000i Storage Arrays
If the XenServer host is connected to the PowerVault MD3000i storage arrays,
on the XenServer host, you can change the SCSI timeout value for the SCSI
device(s) on the PowerVault MD3000i storage arrays. Follow the steps below:
1
Create a new udev rule file with name 96-md3000i-sto.rules at
/etc/udev/rules.d/
and add the following text:
KERNEL=="sd*[!0-9]", ACTION=="add", SYSFS{model}==
"MD3000i", SYSFS{vendor}=="DELL", RUN+="/bin/sh -c
'echo 200 > /sys$DEVPATH/device/timeout'"
2
Save the file. Attach the iSCSI volume to the XenServer host and create
an SR.
3 Adjust the SCSI timeout on the Windows VMs residing on the SR
resident on the PowerVault MD3000i by changing the following registry
setting:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\dis
k\TimeOutValue.
4 Create the value if it is not present. Set this value to 200 .
NOTE: Do not modify the SCSI timeout in the paravirtualized Linux VMs as the
VM virtual disks are not presented as SCSI disks.