Poll: How to find a FC device to boot from in the BCH?

[marie-noelle jeanson_1]

Hi,

I am trying to find out how you would set the boot path to a FC device from the BCH interface. The question really is, how do you figure out what boot path to enter in the BCH PA command, as the search command only displays a device path that is not the whole hardware path to the FC device and since you are offline, you do not have access to usual online commands (ioscan, fcdutil, ...) to figure it out?
Is this something you have done before? In which context?
I am mostly interested in hearing about the process on PA systems, but you may answer for IPF as well.

Thanks in advance for the input,

Marie.

[Michael Steele_2]

With SAN booting 'set_boot' often doesn't work as it is looking for a pri and alt disk in the class 'DISK', i.e., ioscan -funC disk.

So there should be an additional boot manager message displayed on your console, i.e., for secure_path it will be EFI boot manager.

Can you paste in or id the SAN boot manager message?

Here's a doc on SAN booting with secure path: OS050329_CW01

Note the below message mon ami.


During the system boot, interrupt the boot process at EFI boot manager

EFI Boot Manager ver 1.10 [14.60] Firmware ver 2.21 [4306]

Please select a boot option

[Michael Steele_2]

There are some requirements to a SAN boot. What is your SAN setup? Is EMC or XP disk arrays? If so then you'll need secure path.

See link:

http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00403562/c00403562.pdf

[Torsten. · Accepted solution]

Hi Marie-Noelle,

a failed systemboard or a mistake while configuring the path can bring you easily in this situation, where the information about the boot path is gone. In this case, the paper based documentation about the system configuration will usually disappear immediately.

The use of an install media or at least an offline diagostic CD (to run mapper2) is IMHO the only way to get an idea about potential boot devices in this case.

It could be a useful feature to have a command to search the SAN from BCH for boot devices.

Regards
Torsten


@Michael: Please read the question again ;-)

[marie-noelle jeanson_1]

Michael,

I do not have a specific problem to solve, I am working for HP and trying to find out how users do this task as it seems that is not a straightforward task today to find the hw path of the SAN device to be entered at BCH, as the search command returns a device path which is not directly usable as BO P# in this case (not the whole hw path to the device).

Marie.

[Alzhy]

Marie-Noelle (what a nice name I must say),

On my rp8420s and a SuperDome, we have a maintain a table of how LUNS map to a HW Path and since we know Cab/Bay/Chassis/PCI/SBA/LBA path of our HBAs - it is quite easy.

For instance, on an rp8420, my SAN Boot LUN (from the XP) is presented as LUN 1020 (dec) and its full BCH friendly path is:

0/0/12/1/0/4/0.2.19.0.7.15.4

with 0/0/12 - being slot3 a FC-HBA card. It's alternate path is at slot 5 and full hw path of:

1/0/12/1/0/4/0.2.19.0.7.15.4

The last dot notation, 7.15.4 is the BTL designation -- bus, target, lun and there is a formula for this. The 1/0/4/0.2.19.0 portion I can no longer recall but is well documented in the VSA (volume set addressing) documentation at docs.hp.com.

Hope this helps...

[Andrew Rutter]

hi,

2 ways you could do it.

1, boot the support plus media cd and run the mapper tool to list the hardware paths. this will give you all the cards installed, but you still need to know which one to use.

2, from the main menu at BCH go into the information menu, and run the io command to list all hardware paths, or meain menu
Main>in io

Andy

[Alzhy]

Marie-Noelle,

Losing your boot path info due to system board/coreIO or firmware update gone bad should be no excuse fo an admin of a system NOT to be able to figure out the correct boot path.

Better if you have standard LUN numbers of boot LUN as it will be easier but the key here is to throghly understand Fibre-Channel addressing.

If you've a support contract, you may read the page 12 of the following chapter of the HP-UX Recovery Manual:

http://www1.itrc.hp.com/service/iv/docDisplay.do?docId=prodITRC/DE_SW_UX_swrec_EN_01_E/FibreChannel.pdf

[Alzhy]

And with HP-UX servers increasingly becoming "media-less" (meaning no HDD or Optical Drives), the usual solutions of booting off a CDROM or Tape is no longer feasible.

Of course with the proper infrastructure, you can also do a LAN boot.

[Torsten.]

I'm really sure, Marie's question is NOT only "How to do it", but "Why to do it".

In fact, in a big shop it's not unusual to have a special team for HP-UX servers, storage and why not for SAN switches.

If the server is broken and the boot path information is lost, it could be really hard to calculate the needed HW-path and get the needed information about the type of storage device, LUN number, type and domain ID of SAN switch.
Especially at 3 o'clock at night. ;-(

The first part of the path inside the system is the easiest part, but functions like "in io" or "sea" will give only the HBA - nothing else.

In a worst case you have to contact the SAN team and the (why not) XP team to gather the needed information.

In a well zoned environment the server is seeing only his own disks, so a functionality like the good old "IPL> sea ipl" would be a comfortable way to get the path back.

This is my vote.