topic Re: LUN Multipath in Disk Enclosures

LUN Multipath

Mukuld — Mon, 17 Mar 2008 20:47:58 GMT

Hi,

I have a quick question. From EVA8100 all the LUNs except one (Disk 7 - 2.0.3.31) shows 8 paths to one vDisk on all the presented hosts. As for as configuration is concern, all the vDisks are configured exact same way.

-----------------------------------------------
C:\Program Files\Hewlett-Packard\HP MPIO DSM\EVA DSM\x86>HPDSM devices

Device# Device Name Serial No. Active
Policy Disk# P.B.T.L ALB
Paths

-------------------------------------------------------------------------------
------------------------------------------------
1 HP HSV210 600508B40006A99A0000C00000670000 8
SQST Disk 1 2.0.5.26 N
2 HP HSV210 600508B40006A99A0000C00000780000 8
SQST Disk 2 2.0.5.27 N
3 HP HSV210 600508B40006A99A0000C00000F20000 8
SQST Disk 3 2.0.5.28 N
4 HP HSV210 600508B40006A99A0000C00001420000 8
SQST Disk 4 2.0.5.29 N
5 HP HSV210 600508B40006A99A0000C000014C0000 8
SQST Disk 5 2.0.4.30 N
6 HP HSV210 600508B40006A99A0000C000017C0000 8
SQST Disk 6 2.0.3.32 N
7 HP HSV210 600508B40006A99A0000C000016C0000 4
SQST Disk 7 2.0.3.31 N
8 HP HSV210 600508B40006A8880000C00000410000 8
SQST Disk 8 2.0.7.33 N

C:\Program Files\Hewlett-Packard\HP MPIO DSM\EVA DSM\x86>
-----------------------------------------------

Any help would be really appreciated.
Regards

Re: LUN Multipath

Steven E. Protter — Tue, 18 Mar 2008 00:39:43 GMT

Shalom,

I was kind of wondering if 8 paths to every dis k is not inefficient and possibly will fragment the bandwidth between the HBA cards and the desk.

Since the EVA only has two controllers, 2 paths to every disk is usually sufficient.

SEP

Re: LUN Multipath

Mukuld — Tue, 18 Mar 2008 00:54:08 GMT

Hi,

On each EVA controller, we have 4 ports which are connected on fiber switch and thats how host see each vdisk with 8 paths.

regards

Re: LUN Multipath

Duncan Edmonstone — Tue, 18 Mar 2008 07:43:01 GMT

This is a Windows/Storage question - not sure what its doing in the HP-UX section.

You are completely sure that disk 7 is configured the same are you? You've actually checked the presentations thru command view?

Note that disk 7 sees 4 of its 8 paths suggesting that its not configured to be seen out of one controller, or has been presented to the wrong host.

Ho back and check Command View again.

(and SEP... 8 paths are usual for EVA8000 - nothing to worry about there).

HTH

Duncan

Re: LUN Multipath

Amar_Joshi — Tue, 18 Mar 2008 16:21:13 GMT

Not sure if the devices created for EVA disks are sufficient or not? You may wanna try the following command to create all the required device files:

# insf -e

and then check the disks path again.

Back to original question, multiple paths are okey, they will all be taken care of by multipathing software.

Re: LUN Multipath

Phillip Thayer — Wed, 19 Mar 2008 19:37:33 GMT

Review the ports that are added to the vDisk and make sure any redundant ports are added on the vDisk definition in CommandView.