6.0.1

Table Of Contents
Creating a Virtual Compatibility Mode Raw Device Mapping
This option creates a Raw Device Mapping (RDM) le on a VMFS volume and maps a raw LUN to this le.
After this mapping is established, you can access the LUN as you would a normal VMFS virtual disk. The
le length of the mapping is the same as the size of the raw LUN it points to.
-r --createrdm device
When specifying the device parameter, use the following format:
/vmfs/devices/disks/disk_ID:P
Example for Creating a Virtual Compatibility Mode RDM
In this example, you create an RDM le named my_rdm.vmdk and map the disk_ID raw disk to that le.
vmkfstools -r /vmfs/devices/disks/disk_ID my_rdm.vmdk
You can congure a virtual machine to use the my_rdm.vmdk mapping le by adding the following lines to
the virtual machine conguration le:
scsi0:0.present = TRUE
scsi0:0.fileName = /vmfs/volumes/myVMFS/my_rdm.vmdk
Creating a Physical Compatibility Mode Raw Device Mapping
This option lets you map a pass-through raw device to a le on a VMFS volume. This mapping lets a virtual
machine bypass ESXi SCSI command ltering when accessing its virtual disk.This type of mapping is useful
when the virtual machine needs to send proprietary SCSI commands, for example, when SAN-aware
software runs on the virtual machine.
-z --createrdmpassthru device
After you establish this type of mapping, you can use it to access the raw disk just as you would any other
VMFS virtual disk.
When specifying the device parameter, use the following format:
/vmfs/devices/disks/disk_ID
Listing Attributes of an RDM
This option lets you list the aributes of a raw disk mapping.
-q --queryrdm
This option prints the name of the raw disk RDM. The option also prints other identication information,
like the disk ID, for the raw disk.
Displaying Virtual Disk Geometry
This option gets information about the geometry of a virtual disk.
-g --geometry
The output is in the form: Geometry information C/H/S, where C represents the number of cylinders, H
represents the number of heads, and S represents the number of sectors.
N When you import virtual disks from hosted VMware products to the ESXi host, you might see a disk
geometry mismatch error message. A disk geometry mismatch might also be the cause of problems loading
a guest operating system or running a newly-created virtual machine.
Chapter 26 Using vmkfstools
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