Identifying Physical LUNs in an IVM

[Andy Underhill]

Hi, I have a question concerning how to identify LUNs that have been presented to a HPUX11iv3 guest (IVM 4.0). I have a number of blades in different data centres and four storage arrays. I would like to be able to identify a LUN as belonging to an array from within a guest.

On the host it is easy using scsimgr and grep'ing for "Serial number", but within the guest the Serial number has been virtualised and so there is no tie up between physical and virtual LUN. I need to know where the LUN has come from for mirroring reasons.

Can anyone suggest a way of achieving this?

TIA

[Torsten.]

"ioscan" should tell you what it is - file or LVOL or disk.

This is a LVOL:

disk 0 0/0/0/0.0.0 sdisk CLAIMED DEVICE HP Virtual
LvDisk

But thats it. For the guest it is just a SCSI or AVIO disk.

[Duncan Edmonstone]

>> I need to know where the LUN has come from for mirroring reasons.


This suggests you are doing mirroring in the VM guest - you should always try to do that in the VM host or hardware... any particular reason you're trying to do it in the VM guest?

HTH

Duncan

[Johnny Damtoft]

From within the Guest you can not identify the physical LUN or which array it located in, this has to be done from the Host.


FROM GUEST:
# ioscan -fnCdisk
disk 5 0/2/0/0.0.0 sdisk CLAIMED DEVICE HP Virtual Disk
/dev/dsk/c4t0d0 /dev/rdsk/c4t0d0


FROM HOST:
hpvmstatus -P
Device Adaptor Bus Dev Ftn Tgt Lun Storage Device
======= ========== === === === === === ========= =========================
disk avio_stor 2 0 0 0 0 disk /dev/rdisk/disk88

Check the hardware path, and do use xpinfo from the host to identify the physical LUN and detailed information of the array.
# xpinfo -d -l
/dev/rdisk/disk88,00,502,CL1A,4f:02,OPEN-V,40960,00075318,5001,004f,---,SMPL,SMPL,SMPL,SMPL,1,RAID5,1-2,R0001,R0101,R0201,R0301,XP24000,50060e8015263600,ef,00,---,0001263600004f02,---,---,---,---,50060b0000c26203,50060b0000c26202,---,---,---,---,/dev/rdsk/c13t0d2


But there is a way to keep track of this information, however I don't know how. :)
- I was talking to HP about keeping track of assigned LUN's from the Host, and an XP array. There is a was to insert some information on the XP array from the Host, as to which Guest the LUN's are assigned.

Maybe someone can share more about this ??


--
Johnny

[Doug O'Leary]

Hey;

On my IVMs, I did the mirroring on the host system and supplied raw logical volumes to the virtuals. I wasn't thinking of this scenario when I came up with that; however, it sure does fit the bill.

As you mention, the physical disks are virtualized so there shouldn't be any way to identify an actual disk serial number from within the guest directly.

What you might consider trying is somehow encoding the c/t/d numbers into the hpvmmodify command in a method similar to setting up the psuedo mac addresses for the virtual nics. Maybe there's something in the options you can set...

Hope that helps; I'd be curious to find out what you come up with.

Doug O'Leary

[Torsten.]

IMHO the most easy "workaround" is to write down everything you configure ...

[Steven E. Protter]

Shalom,

On Torsten's last post.

Where I stared doing system administration there was an old fashioned paper notebook.

In it were printouts of system configuration, ioscan and such, to be there so we knew what was what in case we had no system.

Came in handy a number of times. Not every problem solution need be high tech.

SEP

[Doug O'Leary]

>>Not every problem solution need be high tech.

Pfft! That's just crazy talk!

lol

Doug

[Torsten.]

From my point of view the situation is like this:

There are some guests on some hosts with some disks assigned and now the question is - where are the data disks?

The best way to avoid this is planning and documentation, IMHO. Even old-fashioned paper based ...

Do you know about change management? ;-))

[Johnny Damtoft]

Hi,

This is what I was refering to, in my prev. post.

http://docs.hp.com/en/B2355-60130/scsimgr.1M.html
It is called: "device identifiers" on XP storage, using the SCSI management and diagnostic utility.

To identify or lable a LUN, use the following command:
# scsimgr set_devid â guest_vme02â â D /dev/rdisk/diskXX

And to read the label again:
# scsimgr get_devid -D /dev/rdisk/diskXX

All of the above is set from the VM Host.

This feature needs to be enabled on the XP array, as you may get the following error if not enabled.

scsimgr: ERROR: LUN /dev/rdisk/disk26 does not support Device Identifier.

Hope this helps. :)

Good luck.

--
Johnny Damtoft

[Johnny Damtoft]

Error in chars, in prev. post.

- I'll try again.


Hi,

This is what I was refering to, in my prev. post.

http://docs.hp.com/en/B2355-60130/scsimgr.1M.html
It is called: "device identifiers" on XP storage, using the SCSI management and diagnostic utility.

To identify or lable a LUN, use the following command:
# scsimgr set_devid "guest_vme02" -D /dev/rdisk/diskXX

And to read the label again:
# scsimgr get_devid -D /dev/rdisk/diskXX

All of the above is set from the VM Host.

This feature needs to be enabled on the XP array, as you may get the following error if not enabled.

scsimgr: ERROR: LUN /dev/rdisk/disk26 does not support Device Identifier.

Hope this helps. :)

Good luck.

--
Johnny Damtoft

[Vinod Kumar Yadav]

Hi,

The HP-UX IVM Guest will always RUN on the HP-UX Hosts Blade Server.

The LUN Coming from Storage always present on Hosts then in the Guest with this command.

#hpvmmodify â P vm00 -a disk:scsi::disk:/dev/rdsk/disk10

Exp:- vm00 is the Name of the Guest Server.

Then run the command #ioscan on the guest
server.Create the device file with command
#insf -e

For identifying the disk information on the Guest Server enter the command.

#hpvmstatus -P vm00 - Got the output like this.

[Storage Interface Details]
Guest Physical
Device Adaptor Bus Dev Ftn Tgt Lun Storage Device
======= ========== === === === === === ========= ===========
Disk scsi 0 1 0 0 0 lv /dev/vg02/rlvol1
Disk scsi 0 1 0 1 0 lv /dev/vg04/rlvol1
Disk scsi 0 1 0 2 0 disk /dev/rdsk/c6t1d2
Tape scsi 0 1 0 6 0 attach /dev/rscsi/c5t0d2

And finally check the.

Disksize with complete disk information on Guest Server & Hosts Server

#diskinfo - It will so same size on both Guest & Hosts Server

For Example:- HP-UX IVM VMHOSTS is Physical Server & VMGUEST Server is the Virtual Server.

Any thing need to be do on the HP-UX VMHosts

Regards
Vinod Yadav