topic Re: Identifying vdisk from host mount point in Disk Enclosures

Identifying vdisk from host mount point

NathanK — Thu, 22 Dec 2005 10:36:10 GMT

I want to be able to remove a lun from a system and know for sure that I am removing the correct one. I see no way to do this easily, but I am sure there is a way.

I am running an EVA 8000 with Windows 2000 (MPIO) and HP-UX (pvlinks) connected. Please help!

Nathan

Re: Identifying vdisk from host mount point

Bernhard Mueller — Thu, 22 Dec 2005 10:49:48 GMT

Nathan,

speaking for HP-UX:

run strings /etc/lvmtab | grep
to make sure you have removed/exported all VGs that used any path/device file to the lun
then
remove the presentation to the UX host and
run ioscan -fnCdisk and will see "NO_HW" on all the paths to the LUN.

the paths will disappear after the next reboot (which is not required).

Regards,
Bernhard

Re: Identifying vdisk from host mount point

NathanK — Thu, 22 Dec 2005 10:57:14 GMT

I guess I should clarify.. What if I have two seperate vdisks. How do I know that I am removing the correct vdisk presentation?

Re: Identifying vdisk from host mount point

Bernhard Mueller — Thu, 22 Dec 2005 11:08:35 GMT

Nathan,

in HP-UX you have ioscan and fcmsutil/fcdutil.

ioscan -fnkCfc
will list FC HBAs
depending on the HBA you have /dev/td# or /dev/fcd# device files
you can run
fcmsutil /dev/td# get remote all
or fcdutil /dev/fcd# get remote all

also in ioscan -fnkCdisk the last number in the HW path represents the LUN# HP-UX wise.

Regards,
Bernhard

Re: Identifying vdisk from host mount point

NathanK — Thu, 22 Dec 2005 11:32:31 GMT

fcmsutil only shows the physical connections (i.e. array level) not the lun level.

Re: Identifying vdisk from host mount point

Bill Costigan — Thu, 22 Dec 2005 19:11:12 GMT

From commandview you can see the LUN #1 being presented to the host for each vdisk.
Let's say vdisk_001 is LUN 6 and vdisk_002 is LUN 17.

The LUN numbers will be the scsi addreses to the hosts. I can't remember exactly where to find this on windows. I know it is in the disk manger, properties, somewhere.

On HPUX it is coded in the device file.
/dev/dsk/cXtYdZ

LUN numbers less than 128 just multiply the 'Y' by 8 and add 'Z'

eg. c10t0d6 = 0 * 8 + 6 = LUN 6
c10t2t1 = 2 * 8 + 1 = LUN 17

if the LUNs are too big you need to extract some bits from the 'X' and multiply it by 128 or 256, don't remember and that gives you the LUN number.

If you need that reply back and I'll look up the details. Same for windows.

BTW, If you are using securepath, you'll need to do this with the hsx devices shown when you do the spmgr display.

Re: Identifying vdisk from host mount point

NathanK — Tue, 27 Dec 2005 08:07:23 GMT

That'll work! Thanks!