How to pan a SAN storage for vSphere environment?

[Minghui]

According to VM SAN book, we can install up to 100 VM guests in a singale LUN.

And my question is:

1. Should we mount different LUNs to each ESX host or al the ESX hosts can share a sigle LUN? Can those hosts access the shared LUN at the same time?

2. Can we mount multiple LUNs to a single ESX host? Can a single VM guest use multiple LUNs at the same time?

3. How to resize a LUN with VM guests on it?

Please kindly answer and povide more instructins. Thanks!!

[AndreTheGiant]

we can install up to 100 VM guests in a singale LUN.

For server VM use 10-20 VM for each LUN.

1. Should we mount different LUNs to each ESX host or al the ESX hosts can share a sigle LUN? Can those hosts access the shared LUN at the same time?

Yes, Yes

VMFS can share a LUN across different ESX.

2. Can we mount multiple LUNs to a single ESX host? Can a single VM guest use multiple LUNs at the same time?

Yes, Yes (the VM will not access the LUN but the files on the VMFS datastore created on the LUN)

You can have that a vmdk disk of a VM is stored on the first datastore, and the other disk is stored on the second datastore (for example...)

3. How to resize a LUN with VM guests on it?

In ESX 4 there are two option: grow and extent.

If suggest to do not resize, but simple create a new datastore.

For some generic information about VMFS see:

http://www.vmware.com/products/vi/esx/vmfs.html

Andre

[krowczynski]

I would recommend you to create different LUNS, an not to place more than 10 VM's or 3000IO on it.

You performance wont't we well.

Create some more LUN's and you will be more sattisfied with your enviroment.

[Minghui]

For our current situation:

1. We hope to build a VM-on-demand environment, so we can't build a predictive scheme for LUN management.

2. We may have to resize or extend an existing LUN to fulfill those on-demand request.

So, can we resize a LUN without stop or move VM guests on it? Or should we use the "grow" function?

[LucyLi]

>So, can we resize a LUN without stop or move VM guests on it? Or should we use the "grow" function?

Yes, you can resize a LUN without stop or move VMs guests on it.

(see vStorage VMFS Volume Grow)

vCenter Server 4.0 allows dynamic expansion of a VMFS volume extent to add capacity to an existing datastore. VMFS Volume Grow is a new method for expanding a datastore without disrupting running virtual machines. After a LUN that backs that datastore is expanded through an array management utility, the administrator can use VMFS Volume Grow to expand the VMFS extent on the expanded LUN. The newly available space appears as a larger VMFS volume (datastore) along with an associated grow event in vCenter Server systems.

For how to increase VMFS volume, see Page104, Increase VMFS Datastores