VMware GSX Server 3 Administration, Administration Manual

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VMware GSX Server Administration Guide
In addition to enabling SCSI reservation on the bus, you need to allow virtual
machines to access the shared disk concurrently. Add the following line to the virtual
machine’s configuration file:
disk.locking = "false"
This prevents the locking of that disk, which permits multiple virtual machines to
access a disk concurrently. Be careful though: if any virtual machine not configured for
SCSI reservation tries to access this disk concurrently, then the shared disk is
vulnerable to corruption or data loss.
Caution: This setting applies to all disks in the virtual machine.
When SCSI reservation is enabled, the system creates a reservation lock file that
contains the shared state of the reservation for the given disk. The name of this file
consists of the filename of the SCSI disk appended with
.RESLCK
.
For example, if the disk
scsi1:0.filename
is defined in the configuration file as
scsi1:0.fileName = "/<path_to_config>/vmSCSI.vmdk"
then the reservation lock file for this disk has the default name
/<path_to_config>/vmSCSI.vmdk.RESLCK
You can provide your own lock filename. Add a definition for
scsi1:0.reslckname
to the configuration file. For example, if you add
scsi1:0.reslckname = "/tmp/scsi1-0.reslock"
to the configuration file, this name overrides the default lock filename.
Caution: Use the same lock filename (for example,
"/tmp/scsi1-0.reslock"
) for
each virtual machine in the cluster. You must also use the same SCSI target for each
virtual machine when you define
scsi1:0.reslckname
. However, the SCSI bus
(
scsi1
in this case) does not need to be the same.
Once SCSI reservation is enabled for a disk — that is, the
scsi<x>.sharedBus =
"virtual"
and
disk.locking
=
"false"
settings are added to the
configuration file for each virtual machine wanting to share this disk — you need to
point each virtual machine to this disk.
To add a virtual disk to a virtual machine, see Adding Virtual Disks to a Virtual Machine
in the VMware GSX Server Virtual Machine Guide .
Issues to Consider When Sharing Disks
• Do not try to share a disk among multiple running virtual machines that are not
collocated on the same host. The disk file itself may be located remotely, but the
virtual machines must be running together on the same GSX Server host. If you