Create RDM on to Local Storage ???

[pvl]

I know that this is "not supported" ... but some time ago I was able to find a post here that described the syntax for creating an RDM that points to local storage ... and now, when I need to do it, I cannot find that information.

Basically, I need to P2V a file server that has nearly a TB of storage on an external cabinet. The ESX server it is going to only has local storage. The plan is to P2V the system drives, then to direct attach the external cabinet to the ESX host, and map the VM to storage on the cabinet using RDMs

I know it can be done but that you have to use the command line to do it ... anyone here done it, know the commands/syntax?

Thnx!

[Texiwill]

Hello,

This is possible. You have to use the SCSI Generic method to get this to work. Or code it into your vmx like so... note this is for a CCISS controller but you can map to any local controller. You can also use any other ScsiBus other than 2, but its what I use. Note however that the :1 should match the scsi id of the device to use. And yes this could also refer to a partition, I think full disks/LUNs work better.

scsi2.present="TRUE"
scsi2:1.present="TRUE"
scsi2:1.deviceType="scsi-passthru"
scsi2:1.fileName="/dev/cciss/c0d1"

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.

CIO Virtualization Blog: http://www.cio.com/blog/index/topic/168354

As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[pvl]

Very nice, thank you. Could I ask that you elaborate just a bit, since I am uncertain exactly what I need to do. Are you saying that I simply edit the vmx file to add these lines:

scsi2.present="TRUE"

scsi2:1.present="TRUE"

scsi2:1.deviceType="scsi-passthru"

scsi2:1.fileName="/dev/cciss/c0d1"

(oh, and yes it happens to be an HP server, as well) Does it matter where in the VMX file I put these? Do I still have to use a vmkfstools command to do create the RDM files? This particular cabinet has I believe 3 or possibly 4 arrays, each with a single logical drive ... how do I reference in each RDM a specific logical drive?

And, does using the "SCSI Generic method" dictate a different vmkfstools command syntax, or how do I use this method and why would I choose one method over the other?

Peter

[Texiwill]

Hello,

The full instructions are referenced in my book, but you will first need to determine which cciss device to use to do that use:

fdisk -l

If you have not configured anything NOT in use by ESX then you will need to do so. If the fdisk command sees the LUN it will be named something like

/dev/cciss/cXdY

Or for a partition

/dev/cciss/cXdYpZ

Where X, Y, and Z are numbers.

Then you edit the VMX file for the VM, powered off, to be used and add the apropriate lines. Power on the VM and the device can now be seen. No need to use vmkfstools for this as you are using the SCSI passthru method.

Sometimes you can see local drives within the VIC if you specify to add a SCSI Generic device.

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.

CIO Virtualization Blog: http://www.cio.com/blog/index/topic/168354

As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[dfir]

Hi Peter,

Did you manage to get RDM working? I'm having trouble getting it to work.

Thanks,

Jesper

[Photubias]

Hi,

This is another way entirely to do it:

Go to the console (also works 'UNSUPPORTED' in ESXi).

First detect your disk using this commando:

#ls -al /vmfs/devices/disks/

You will see symlinks to all your disks, remember their names (something like vml..vmdk

Now you created a 'vmdk'-file inside the folder of your VM.

Only thing left to do is go to vcenter (vSphere client or ViClient) and add an existing Hard Disk to your VM.

Greetings,

Photubias