How many VMs inside a LUN

[ditro2001]

Hello together,

with ESX3.5 we build small LUNs 300-600 GB and approximately 5 VMs in the LUNs.

How do you configure you LUNs in your environment.

I'd like to use bigger LUNs in order to be more flexible. Is there a maximum of VMs inside a LUN.

I mean with more VMs in the same LUN the performance decrease.

kind regards

Dennis

[thb_]

in general without knowledge of the enviroment i also like to go with:

• 10 high I/O VMs per datastore
• 15 average I/O VMs per datastore
• 20 low I/O VMs per datastore

Detailed Infos see here:

VAAI and the Unlimited VMs per Datastore Urban Myth » boche.net – VMware vEvangelist

[lvaibhavt]

Hi,

You can use bigger LUN's in the environment ... 2TB you can use in ESX 3.5 ...

number of vm's in a lun in my knowledge does not matter .... it is the lun presented on how many hosts that matters

[Cyberfed27]

There was an old thought process from back in the ESX 3.x days that LUNs should only be 500GB.

But those days are gone, I've seen environments use all kinds of sizes.

Keep in mind your SAN will also dictate how big you should make your LUN's for best performance. In some cases a single VM can be given its own LUN/Datastore. It all depends on many factors.

General purpose VM's with no special performance requirements we tend to use 1TB datastores.

[Duncan Epping]

It is difficult for us to say as it will depend on various things like:

• Array type used
• VAAI capable?
• RAID type
• RTO (for backup)
• Performance requirements
• etc

Maybe these will help:

http://www.yellow-bricks.com/2011/07/29/vmfs-5-lun-sizing/

http://www.yellow-bricks.com/2009/12/23/iops/

But those are mainly about performance, make sure to keep RTO in to account. How long will it take you for instance to restore a 2TB LUN?