Installation guide

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VMware ESX Server Administration Guide
Running Microsoft Cluster Service
Microsoft Cluster Service should operate normally in the virtual machines once it is
installed.
Note: Some disk errors are recorded in the Windows event log in normal operation.
These error messages have a format similar to
The driver detected a controller error on
\Device\Scsi\BusLogic3
They should be reported periodically only on the passive node of the cluster and
should also be reported when the passive node is taking over during a failover. The
errors are reported because the active node of the cluster has reserved the shared
virtual disk. The passive node periodically probes the shared disk and receives a SCSI
reservation conflict error.
VMFS Locking and SCSI Reservation
For a shared SCSI disk that can be accessed by multiple ESX Server machines, two
kinds of locking may be in use. These two kinds of locking are somewhat independent
and can cause confusion. The shared SCSI disk may be on shared SCSI bus or, more
likely, on a storage area network (SAN).
VMFS File System Locking
The first kind of locking is VMFS file system locking. ESX Server locks VMFS file systems
on a server level when a VMFS file system is configured as a public or shared file
system. This locking is done in order to ensure that there is no corruption caused by
multiple accesses to the file system by different hosts.
If a VMFS-1 volume is configured in public mode, only one server can ever access that
VMFS at a time. If one server is accessing the VMFS-1 volume, through a virtual
machine or a file system command, then a file system operation by another host fails.
For example, a vmkfstools command fails with a message that says:
vmkfstools: file system is locked by another server. Use
'vmkfstools --recover' to unlock file system if no other
server is accessing
Typically, you should not run vmkfstools --recover at this point, since
another host is actually using the file system. The error message simply indicates that
this server cannot access the VMFS until the other server has finished accessing it.
However, if a server fails while accessing the file system, the file system may stay in the
locked state and you may need to run vmkfstools --recover.