topic Re: Adding LUNS to Windows 2000 servers on XP512 Disk Array in Disk Enclosures

Adding LUNS to Windows 2000 servers on XP512 Disk Array

Mahendra Luhar — Tue, 12 Oct 2004 09:08:21 GMT

What is the criteria for configuring LUN 0 on an XP512 Array?
Our existing configuration consisted of 2 LUNS
LUN 6 and LUN 7. LUN 6 composed of 15 * 7GB (LUSE) devices, LUN 7 single device of 7GB.
The addition of LUN 8 not visible on the server. The only way we could see and configure the the extra LUN was by changing the LUN ID to 0.
The HBA is a 1GB Q Logic 2200F connected to the XP512 via a Brocade 2800 silkworm.
Can anyone explain what's going on here, please ?

Re: Adding LUNS to Windows 2000 servers on XP512 Disk Array

krusty — Wed, 13 Oct 2004 11:03:50 GMT

The problem here is not about LUN 0, but about a registry setting. Windows does require LUN 0, but most of the HBA vendors (Emulex, QLogic, Agilent) have worked around this issue.

The problem is Windows only recognizes LUNs 0-7 by default. Refer to this Microsoft article on this issue.

http://support.microsoft.com/default.aspx?scid=kb;en-us;310072

Microsoft also has issues with non-consecutive LUNs (called "sparse LUNs"), so if you skip a LUN, the OS will not see the LUN without some registry mods also.

Re: Adding LUNS to Windows 2000 servers on XP512 Disk Array

Mahendra Luhar — Wed, 13 Oct 2004 11:08:20 GMT

Thanks for your help. I'll get the Windows support boys onto this