Specifications

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VMware GSX Server Administration Guide
Using SCSI Reservation to Share SCSI
Disks with Virtual Machines
GSX Server permits the sharing of a preallocated virtual disk with multiple virtual
machines running on the same host, provided the disk in question is a SCSI disk.
When the disk is shared, all virtual machines connected to the disk use the SCSI
reservation protocol to write to the disk concurrently.
Clustering software must be installed in each virtual machine that intends to share a
SCSI disk. Enabling SCSI reservation in and of itself does not automatically mean that a
running virtual machine is a participant in the SCSI reservation protocol.
Note: Although physical disks can be used with SCSI reservation, such use is
considered experimental. Only the use of preallocated virtual disks is fully supported
with SCSI reservation. When you create a new virtual machine, or add a new virtual
disk to an existing virtual machine, GSX Server creates a preallocated virtual disk by
default.
Note: This feature is advanced; use it only if you are familiar with SCSI in general and
the SCSI reservation protocol in particular.
The following sections describe how to use SCSI reservation to share disks among
multiple virtual machines.
• SCSI Reservation Support on page 193
• Enabling SCSI Reservation on page 194
• Issues to Consider When Sharing Disks on page 196