Best practice LUNs on iSCSI target

[powadha]

I'm connecting my ESX lab to a QNAP iSCSI target and wonder what the best practice is for creating LUNs on the target. I have two servers each connecting to its own target. Should I create a LUN for every vm I'm planning to create on the Lab or is it better to create a larger LUN and have multiple vm's per LUN? Does placing multiple vm's on a LUN have concequenses for HA or FA?

Regards

[idle-jam]

the better practice is to have a large LUN and multiple VM on the LUN this make management easier. then with the LUN is formated as VMFS/Datastore you will create VMDK = virtual drive to the OS.

[rickardnobel]

powadha wrote:

Does placing multiple vm's on a LUN have concequenses for HA or FA?

No, it is fully supported. And it will even be a higher chance that all hosts has access to all data when using a large LUN with VMFS instead of multiple LUNs with the risk of masking incorrectly.

[JohnADCO · Accepted solution]

There is always a trade off.....

iSCSI reservations are per LUN.    If you get to many guests on the same lun it becomes an issue and yes we have seen it.

Thin provision for sure.   That way you can make your luns smaller and still get several VM's on each them.

[powadha]

Thanks everyone, great help!

Now there's only one thing left I forgot to ask. I run two servers in the lab. I can create a target (and a say 500 GB LUN) for each and connect the servers to its own target and LUN on the QNAP. Now I could just go for one target and one LUN and connect both servers to the one target and LUN (1TB).

Its a lab so there wont be too much going on. I guess I wont be running more then 5-8 vm's on each. Any thoughts on this?

Regards

[rickardnobel]

There should be no problems with running 5-8 virtual machines on your common LUN.