RAW device mappings size question

[ChrisI88]

We are running VMFS 3 with ESX 4.1 hosts.

I'm finding that there is a limit on the size of a RAW device map of 2TB - 512 bytes but that you actually make it bigger but it is not-supported.

I'm just looking for conformation on this ?   We are looking to have a drive of several TB is there no way to do this with a single datastore ?

Any information of this would be greatly appreciated.

[vmroyale]

Hello.

2 TB - 512 bytes is the largest supported size in 4.1, as detailed in the Configuration Maximums document.  In vSphere 5, physical RDMs greater than 2 TB are supported.

Good Luck!

[ChrisI88]

Yea I saw that in the Configured max guide for 5.0 but I wasn't sure what it meant.

Do you happen to know how vmware defines a physical compatibility RDM vs a virtual compatibility RDM ?

[a_p_ · Accepted solution]

The basic difference between physical (also known as pass-through) RDMs compared to virtual RMDs is that RDMs in physical compatibility mode are not affected by snapshots. Since virtual RDMs are affected by snapshots and the snapshot files are virtual disks, the limit of ~2032GB still applies.

André