J_Wright
Enthusiast
Enthusiast

Optimizing storage across LUNs?

Does anyone know of a piece of software or a script that will take all of your vm's in a specific cluster and give you suggestions on what LUN to put them on? I am wanting to optimize my storage. I have done this manually for one of my clusters, but it would be nice for a script or piece of software to tell me what LUN would be the best fit rather than do it by hand

Thanks,

J

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3 Replies
lamw
Community Manager
Community Manager

There are best practices out there from VMware and probably from storage vendors on how many VMs you should put on a particular LUN, this number is usually 10-20. We've gone ahead and defined standard sizes which is also useful for capacity manamgent so you know exactly how many shells you have at any given point. In terms of automatated tools, not really. What I've done is actually periodically poll the ESX Hosts from specific clusters and update a webpage on the disk capacity and number of VMs currently hosted on a LUN and based on our standard shells, the number of VMs that can possibly go on there based on a standard size. You can do something similiar and check the page to see which LUNs may be over prescribing. You definitely want to leave some room 20-30% for snapshots and growth. There is also a script out there that currently multipaths your storage routes so that you have an active/passive setup, but it'll peridocially change the path to even out the paths it uses to get to storage based on the number of blocks transfered or time duration.

I would also be interested to see if others have any other suggestions, but as far as I Know, is this going to be a manual process and will require some bookeeping if you want to stay within your threshold limits without overtaxing a LUN with contention.

J_Wright
Enthusiast
Enthusiast

Yeah, I have done all that. I usually don't go over 12 vm's per LUN myself. It just would be easier for me if I could find something to automate it. I created an excel spreadsheet and manually optimized all the servers myself. I am surprised knowone has done this yet. It would be a very helpful tool for us who have to do this all the time. I have pinged a couple of my scripting buddies to see if they could come up with a script for me, but I didn't want to re-invent the wheel if there was something that was already out there. If you here of anything please let me know

Thanks,

J

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lamw
Community Manager
Community Manager

I'm not sure if you've seen these two videos:

http://www.vimeo.com/1053282?pg=embed&sec=1053282

I actually just found this out today, so I'm sure with some clever powershell calls, you can pre-define a max # of VMs per LUN and this can automatically choose the first LUN that is free.