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Matthew_Luzitan
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Best Practice for setting up SAN Volumes

When running Virtual Machines from a iSCSI SAN what is the best practice for setting up the SAN volumes?

1. Create individual volume for each virtual machine?

2. Create one giant volume for all virtual machines?

3. Create a set of volumes that would each house several Virtual Machines.

If 3, what criteria should I use in determining what VMs should run on what volume?

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oreeh
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As usual - it depends.

One big LUN isn't a good idea - especially if your iSCSI SAN is from the "low end".

One LUN for every machine is ok - but there's a limit of the max. number of usable LUNs in ESX.

So your best bet is the third option.

500GB - 2TB is the "best practice" recommendation regarding LUN size.

Make sure to mix high and low utilized VMs in the LUNs or create dedicated LUNs for high utilized VMs.

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oreeh
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As usual - it depends.

One big LUN isn't a good idea - especially if your iSCSI SAN is from the "low end".

One LUN for every machine is ok - but there's a limit of the max. number of usable LUNs in ESX.

So your best bet is the third option.

500GB - 2TB is the "best practice" recommendation regarding LUN size.

Make sure to mix high and low utilized VMs in the LUNs or create dedicated LUNs for high utilized VMs.

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Odurasler
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I'm in the same boat, and based on some unforseen circumstances I might redo the way I have my SAN laid out. Here is my current configuration:

-EMC CX3-10

-15-300GB broken down to 2-7disks RAID 5 set with 1 spare

-each RAID set is one big LUN, around 1.6TB

I'm thinking of implementing this configuration:

-1 Big RAID 5 (14disks) with several smaller LUNs (250-500GB)

-each LUN will accommodate 8-12VMs

What do you think?

What have you decide on doing to your environment?

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esiebert7625
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Here is some good reading on this subject...

SAN Configuration Guide - http://www.vmware.com/pdf/vi3_esx_san_cfg.pdf

SAN Conceptual and Design Basics - http://www.vmware.com/pdf/esx_san_cfg_technote.pdf

SAN System Design and Deployment Guide - http://www.vmware.com/pdf/vi3_san_design_deploy.pdf

To use extents or not? - http://www.vmware.com/community/thread.jspa?threadID=81494&tstart=100

LUNS - http://www.vmware.com/community/thread.jspa?messageID=333672&#333672

LUNS Size - http://www.vmware.com/community/thread.jspa?threadID=36725&start=0&tstart=0

Sizing LUN for enough free space after VM - http://www.vmware.com/community/thread.jspa?messageID=649338

Smaller LUNS or Larger LUNS - http://www.vmware.com/community/thread.jspa?threadID=90203

Configuring iSCSI in a Vmware 3 environment - http://www.vmware.com/pdf/vi3_iscsi_cfg.pdf

Ethernet-based Storage Configuration - http://www.vmware.com/pdf/iscsi_storage_esx.pdf

iSCSI , NAS and IP Storage Configuration for Vmware ESX Server - http://download3.vmware.com/vmworld/2006/tac9722.pdf

iSCSI Target Solution - http://www.vmware.com/community/thread.jspa?messageID=613475

VM Disk Scenario’s and Performance - http://www.vmware.com/community/thread.jspa?messageID=661499

Choosing and Architecting Storage for your Environment - http://download3.vmware.com/vmworld/2006/adc0135.pdf

Larger LUNS = More Disks = More Performance - http://www.vmware.com/community/thread.jspa?threadID=84843&tstart=0

ESX Storage Virtualization Insights - http://www.vmware-tsx.com/download.php?asset_id=40

Odurasler
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Great info!!!

Thanks!!!

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CXSANGUY
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I'm in the same boat, and based on some unforseen

circumstances I might redo the way I have my SAN laid

out. Here is my current configuration:

-EMC CX3-10

-15-300GB broken down to 2-7disks RAID 5 set with 1

spare

-each RAID set is one big LUN, around 1.6TB

I'm thinking of implementing this configuration:

-1 Big RAID 5 (14disks) with several smaller LUNs

(250-500GB)

-each LUN will accommodate 8-12VMs

What do you think?

What have you decide on doing to your environment?

I know the question has already been answered but wanted to point out that the way you already have it is a valid config and the way VMware instructs us to instruct end-users (Not necessarily from a size standpoint but from a 1 VMFS LUN per RAID GROUP rule standpoint). The proposed way really isn't valid. What you should be doing instead, if you wish to go that route, is using equally sized 4+1 RAID 5 Groups combined into Striped MetaLUNs. Then carve your LUNs of whatever sizes across all spindles.