nnoel
Contributor
Contributor

Expand Physical RDM beyond 2TB

I have a 2TB physical RDM drive on a server that is nearly full so I need to expand it.  I am running vSphere 5.0.0 Build1024429.  From my research i should be able to attach luns larger than 2TB with this version.  If I try to add space to the current lun I receive an error that it is not allowed, the maximum is 2TB.  If I try to create and attach and new lun over 2TB I create the same maximum error.  Is there some other configuration that needs to be done before I can create or expand over 2TB?

Thank you for your help,

Natalie

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6 Replies
a_p_
Leadership
Leadership

Has the datastore - which contains the RDM .vmdk mapping file - been formatted or upgraded to VMFS5 (rather than VMFS3)?

Before expanding the LUN, you should also ensure that the guest OS supports the new LUN size!

André

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vmroyale
Immortal
Immortal

Is the VM's working directory located on a VMFS-5 datastore?

Brian Atkinson | vExpert | VMTN Moderator | Author of "VCP5-DCV VMware Certified Professional-Data Center Virtualization on vSphere 5.5 Study Guide: VCP-550" | @vmroyale | http://vmroyale.com
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nnoel
Contributor
Contributor

The RDM mapping file is located in a datastore that is VMFS 5.54, Maximum File Size 2TB and Block Size 1MB.  Should I change the Maximum File Size and Block Size?

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nnoel
Contributor
Contributor

The VMs working directory is located in an NFS datastore formatted VMFS 5.

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a_p_
Leadership
Leadership

To me this sounds more like a limitation of the NAS system than ESXi. With VMFS5, ESXi uses a unified block size of 1MB for file sizes of up to ~64TB.

André

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nnoel
Contributor
Contributor

This morning I created a fiber channel lun over 2TB and attached it successfully to an ESX host to test storage and ESXi.  That worked okay.  Then on the storage array I expanded a test RDM lun that is mounted to a test server to over 2TB.  The server sees the new size.  Also my Netapp SnapDrive software sees the new size.  Partition Manager has been working on the resize for awhile now. 

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