James1955
Contributor
Contributor

Luns presented to new VM

ESX 3.0.2, VCenter 2.5.0

I have created a new LUN on my san,

On ESX

Configuration > Storage arrays > rescan luns and I can see my new lun (host id 43)

The problem is that when I create a new VM and go to select my LUN (as an RDM) I can only see luns 0 - 39?!

I'm sure I remember esx has a setting to not show more that 40 luns, and I need to go into the advanced settings to change this.....BUT can I find it in here!!

Many thanks

J

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7 Replies
JonRoderick
Hot Shot
Hot Shot

Hmm, are you thinking of the Disk.MaxLUN value in the Advanced config? The max is 256 (so maybe not what you're talking about here - apologies if it's not!)

I can't think of another setting that would limit the number of scanned LUNs to 40 though....

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James1955
Contributor
Contributor

Cheers Jon, yes I found that setting but I'm well inside that Smiley Wink

I may be thinking of something else that had a 40 limit, but something in the back of my mind is telling me I have changed this setting before on some other esx servers I built.

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JonRoderick
Hot Shot
Hot Shot

Ah, sounds as though you probably just need to consult that clear and concise documentation that we all no doubt put together when configuring all this stuff. 😛

Don't suppose you upgraded from an earlier version of ESX and that still has a lower MaxLUN value configured or something like that?

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James1955
Contributor
Contributor

Upgrade...whats that;)

I avoid the pain of upgrades and just build each new time I want a new version (3.0.1 - 3.5.0)......the luxary of a spare blade!

If all else fails...read the documentation .....now where did I put it..

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espi3030
Expert
Expert

James,

I understand your frustration, I don't like when that happens to me (you know something to be true but can't remember how or why). I have attached a document that may be able to help, though I did not see any limitations with 40 in it. Hope this helps!

James1955
Contributor
Contributor

Thanks for that .pdf, no mention of the limits on it.

I'm only getting this problem on my VC 2.5.0 management box but not on my 2.0.1 management box so wander if its an VC problem?

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James1955
Contributor
Contributor

Ok all sorted.

The lun was already connected to my p2v helper machine on the same esx server (helper machine was shut down). It appears that within the same esx host you can't present a lun to a server if its already connected to another (even if that server is in a downed state).

Oddly another esx server can see and use that lun though if the conditions above are met!

Thanks for the help.

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