How to add a raw mapping device on VMware

VMware ESX Server offers two choices for managing disk access in a virtual machine—VMware Virtual Machine File System (VMFS) and raw device mapping (RDM). It is very important to understand the I/O characteristics of these disk access management systems in order to choose the right access type for a particular application. Choosing the right disk access management method can be a key factor in achieving high system performance for enterprise-class applications.

Basically you can read few VMware RDM related guide from VMware such as: http://www.vmware.com/pdf/esx25_rawdevicemapping.pdf and http://www.vmware.com/resources/techresources/1040

I would like to share “How to add a raw mapping device on VMware” in my VMware ESX development box together with SuSE Linux Enterprise Server 9 VMware guest.

Click on SLES 10 VMware guest in my Virtual Infrastructure Client
Click Edit Setting
Click Add
Select Hard Disk
Click Next
Selecet Raw Device Mappings
Click Next
Select Target LUN
/vmfs/devices/disks/vmhba0:0:16:0
/vmfs/devices/disks/vmhba0:0:22:0
Click Next
Select Store with Virtual Machine OR Specify datastore
Click Next
Select Compatibility
Choose physical (allow the guest operating system to access the hardware directly. Taking a snapshot of this virtual machine will not include this disk)
For Virtual (it’s allow the virtual machine to use VMware snapshots and other advanced functionality
Click Next
Select Virtual Device Node -> SCSI (0:1)
Click Next
Ready to Complete
Click Finish
Click OK

Done!

As you can see from pictures show above, SLES 9 with 200G Raw Device Mapping Drive created.

SSH to SLES 9 and type:

rescan-scsi-bus.sh
cat /proc/partitions

You should be able to see new RDM drive and you can continue with fdisk or configure raw disk.

Additional Tips:
How to check VMware ESX version?
SSH to VMware ESX Server, type:
vimsh -n -e ‘hostsvc/hostsummary’ | grep fullName

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How to add a raw mapping device on VMware