For Windows hosts, the OS will only scan for LUNs up to 255.
So practically speaking, you can't map more than that many to a single host.
The problem kicks in if you have multiple hosts though - they'll each only scan as far as LUN 0xFF so you'll have to start LUN offsetting. Not the end of the world, but somethign that's definitely a lot easier if you do it pre-implementation - having to unmap and remap a bunch of LUNs later is a massive nuisance.
I read that Windows can detect LUNs 0-255 per target. If you are zoned to more than one array (target), can you exceed the 255 limit? This is important since I want to make sure that a Windows server can be used to manage an environment with a large number of Symms. The sum of all the gatekeepers from all the managed arrays on the server may exceed the 255 device limit in a large environment. If the limit is indeed per target, then we will not run into any issues since we only assign about 8 gatekeepers to the server for each array.
"For Windows hosts, the OS will only scan for LUNs up to 255"... this one sounds like 255 TOTAL , single or multiple targets do not matter. As Dynamox mentioned, just cross check
Ed_R1
53 Posts
0
December 9th, 2009 03:00
Quite a broad question, but ... well, yeah.
For Windows hosts, the OS will only scan for LUNs up to 255.
So practically speaking, you can't map more than that many to a single host.
The problem kicks in if you have multiple hosts though - they'll each only scan as far as LUN 0xFF so you'll have to start LUN offsetting. Not the end of the world, but somethign that's definitely a lot easier if you do it pre-implementation - having to unmap and remap a bunch of LUNs later is a massive nuisance.
jaimalhan
2 Posts
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December 9th, 2009 19:00
I want to know this limit for HPUX and Solaris.
Can you please help.
dynamox
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December 9th, 2009 20:00
HPUX 11i v3 - 16384 LUNs (Maximum 32 paths per LUN)
HPUX 11i v2 - 4096 LUNs (maximum 8 paths per LUN)
HPUX 11i v1 - 2400 LUNs
dynamox
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December 9th, 2009 20:00
Solaris 9/10 - Emulex driver - 255 LUNs per target
Solaris 9/10 - Leadville driver see this link
http://nixstor.blogspot.com/2007/12/solaris-leadville-driver-stack.html
SKT2
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December 9th, 2009 21:00
HP-UX 11i V2 has lesser LUNs mentioned comapred to v1 . Hop that is a typo?
dynamox
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December 10th, 2009 03:00
qciti
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December 21st, 2009 15:00
dynamox
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December 21st, 2009 18:00
it's per target. Might want to check your HBA documentation as well but the numbers you are talking about ..you will be ok.
http://technet.microsoft.com/en-us/library/cc773268%28WS.10%29.aspx
SKT2
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December 21st, 2009 22:00
dynamox
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December 22nd, 2009 05:00
i don't think it's 255 total, it's 255 per target, see here
http://support.microsoft.com/kb/310072