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Table Of Contents
Figure 184. Port Reassignment
storage
10.0.0.1
10.0.0.2
storage
10.0.0.1
10.0.0.1
10.0.0.2
With this form of array-based failover, you can have multiple paths to the storage only if you use multiple
ports on the ESXi host. These paths are active-active. For additional information, see iSCSI Session
Management.
Path Failover and Virtual Machines
A path failover occurs when the active path to a LUN is changed from one path to another. Typically, the
path failover occurs as a result of a SAN component failure along the current path.
When a path fails, storage I/O might pause for 30-60 seconds until your host determines that the link is
unavailable and performs the failover. If you attempt to display the host, its storage devices, or its
adapters, the operation might appear to stall. Virtual machines with their disks installed on the SAN can
appear unresponsive. After the failover, I/O resumes normally and the virtual machines continue to run.
A Windows virtual machine might interrupt the I/O and eventually fail when failovers take too long. To
avoid the failure, set the disk timeout value for the Windows virtual machine to at least 60 seconds.
Set Timeout on Windows Guest OS
To avoid disruptions during a path failover, increase the standard disk timeout value on a Windows guest
operating system.
This procedure explains how to change the timeout value by using the Windows registry.
Prerequisites
Back up the Windows registry.
Procedure
1 Select Start > Run.
2 Type regedit.exe, and click OK.
3 In the left-panel hierarchy view, double-click HKEY_LOCAL_MACHINE > System >
CurrentControlSet > Services > Disk.
vSphere Storage
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