Thin provisioning

[gmaze]

I know this question has been asked alot. However with thin provisioning does the size of a LUN make a difference. I was thinking the larger the LUN the more efficient use of thin provisioning would be. In the past I have always used 500GB LUN'S but now I am thinking about 2TB LUN'S. Any thoughts would be appreciated.

[vmroyale]

Hello.

with thin provisioning does the size of a LUN make a difference.

The size of the LUN itself doesn't matter.

In the past I have always used 500GB LUN'S but now I am thinking about 2TB LUN'S.

Are you referring to block sizes used on the LUN specifically? If so, there is an excellent post and discussion on this topic over at Duncan's site that should clear it all up. Look specifically at the comments by Satyam Vaghani.

Good Luck!

[gmaze]

Yes. This helps. Very good information. I still wonder about the size of the the LUN? With thin provisioning you will have a lot more space to work with which allows for more VM Gusts to reside on it. This might cause a lot of traffice on this one LUN. That is also a concern of mine. Maybe I worry to much. Most posts on this type concern have stated to use between 400GB and 800GB LUN'S. Does this change with thin provisioning though?

[vmroyale · Accepted solution]

The general rule of thumb is 12-15 powered-on VMs per LUN, but this all depends on the workloads and their requirements. The use of thin provisioning can definitely impact the sizes of the LUNs you will use. You wouldn't want to build out a 800 GB VMFS volume and then put 15 virtual machines on it that utilize 30% of the LUN. You will want to put a lot of calculated thought into determining the right size for your particular setup. Also, remember to set up your storage alarms so that if a volume starts running out of space you know about it before it gets there.

[gmaze]

Thanks. That's what I thought. I guess I just needed another opinoin to ease my mind.