I would say because of the size RDMs are a better way to go, I say this mostly because I dont like the idea of entire datastores having 1 VMDK file filling them up (and I hope you don't consider ...
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I would say because of the size RDMs are a better way to go, I say this mostly because I dont like the idea of entire datastores having 1 VMDK file filling them up (and I hope you don't consider extents...). Also, depending on if you use virtual or physical mode RDMs you either gain the benefit of it being treated like a VMDK file (cloning, snapshoting, etc) in virtual mode or in physical mode you can use virtual w/ physical server clustering. RDMs also allow you to re-present the disk to a physical host if you need to move the server to physical at a later time. There is no risk to vMotion capability using RDMs in physical or virtual compatibility mode, excluding using some form of clustering solution (i.e MSCS). As far as increased complexity, you just need to be aware that the LUNs are used as RDMs and that all the hosts in your cluster are presented the LUNs in the same fashion. It really comes down to your preference, you can have a bunch of datastores dedicated to this one server (probably completely full and at their size limitation without extents). That, or you can have a few LUNs on each host as RDMs presented to this guest for access and have to be aware that its setup that way.