ISCSI vs SAS with ME4024

I'm spec'ing out a setup for a client. They asked for 3 servers with a single SAN
I'm currently eyeing the Poweredge R640's and an ME4024 SAN.

I'll also do a price compare on the vSAN option so the client can see an alternative.

My biggest questions come with the SAN configuration and the support for the 2 connection methods.
ISCSI seems pretty straight forward and should just work for the application, but it will require purchasing some 10Gb switches adding to the cost.

Shared SAS came up in some of my research, but all I can find is about 10 years out of date.

From what I've read It looks like you can direct attach it to each of the hosts and it can act as their single shared datastore to run VM's from and vMotion between them. However I do have some questions about oddities I've read.

If I configure the ME4024 with various tiers of storage and RAID will it be able to present that as a coherent datastore across the Shared SAS connection or do they have to be set up as JBOD for a SAS connection, or some combination?

How well does vSphere handle Shared SAS from a reliability standpoint? It's going to a client and they won't have a dedicated IT guy so I don't want to be getting calls from them every week.


Anything else I might be missing when making the decision?



0 Kudos
1 Reply

I've just setup a SAS based ME4024 for one of my customers.

However, this customer uses only two hosts, which allowed me to connect 2 SAS ports from each host to each ME controller. Remember that a given pool/LUN is only available through either Controller A, or B and will only fail over in case of a controller failure.
In case of direct connections, if e.g. a cable fails, that ESXi host will lose connection to the LUNs on that controller.

With more than 2 host - if high availability is required - SAS (or any other direct attached option) may not be no option, and you should look into configuring 2 switches.


0 Kudos