To find out if the disk is an internal disk or an external disk.

[akshata bv]

Hi,

I have been put across with a question. How does one find out whether a particular disk is an internal disk or an external disk.

Regards
Akshata

[Patrick Wallek · Accepted solution]

There is no real easy way.

The main thing you need is to be familiar with the SCSI hardware paths to the internal disks on your servers.

One one of my L boxes I've got the following disks:

Output of 'ioscan -kC disk'

H/W Path Class Description
=======================================================================
0/0/1/1.0.0 disk IBM DMVS18D
0/0/2/0.0.0 disk SEAGATE ST318404LC
0/0/2/1.2.0 disk HP DVD-ROM 304
0/4/0/0.1.16.0.0.0.0 disk HP A6189A
0/4/0/0.1.25.255.0.0.0 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.25.255.0.0.1 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.25.255.0.0.2 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.25.255.0.0.3 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.25.255.0.0.4 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.25.255.0.0.5 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.25.255.0.0.6 disk ADTX AXRR-LM000F-FL
0/4/0/0.1.26.255.0.0.0 disk STK BladeCtlr B210
0/4/0/0.1.27.0.0.0.0 disk HP A6218A
0/7/0/0.1.16.0.0.0.0 disk HP A6189A
0/7/0/0.1.22.255.0.0.0 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.22.255.0.0.1 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.22.255.0.0.2 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.22.255.0.0.3 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.22.255.0.0.4 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.22.255.0.0.5 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.22.255.0.0.6 disk ADTX AXRR-LM000F-FL
0/7/0/0.1.24.255.0.0.0 disk STK BladeCtlr B210
0/7/0/0.1.26.0.0.0.0 disk HP A6218A

In the listing above the disks in the 0/0/1 and 0/0/2 paths are internal. All the rest are external fibre attached.

[Steven E. Protter]

Shalom,

I use a dd command

dd if=/dev/dsk/c1t1d0 of=/dev/null bs=1024

Then I look for the flashing green light.

SEP

[akshata bv]

Is there a reason as to why the internal disks have been given number 0/0/1 and 0/0/2 and not any other number?

Regards
Akshata

[Patrick Wallek]

On my L box that the output is from, that is the internal hardware path to the disk.

There will generally be default, hard set, paths for internal disks. The L/rp54xx series have the slots labeled so you can tell what the path is. Other models of machines should be similarly labeled, but may not share the same internal path. It can be server specific.

[akshata bv]

Partrik,

I really thank you for taking time to answer my quires.

Cheers
Akshata

[Sandman!]

The closest you can come to doing this is by searching (SEA) for bootable devices from the BCH (Boot Console Handler) menu. At the BCH menu type "sea" and it'll output something like (assuming your boot disk is mirrored):

P0 0/0/2/0.6 intscsia.6 Random access media
P1 0/0/2/1.6 intscsib.6 Random access media

You can see that the internal disks are designated as "intscsia.6" or "intscsib.6" which are your internal disks. It would be nice if ioscan had an "int_bus" Class in addition to the "ext_bus".

The downside is that you need to reboot your system, interrupt the boot process and get to the BCH prompt in order to see the above information.

[Bill Hassell]

The problem is that *EVERY* major product line of HP hardware has a different hardware structure. The numbers you see in the path correspond to the backplane, internal adapters, I/O cards, etc. Some (high end) boxes have very long path descriptions. From the hardware's perspective, there really isn't the concept of internal or external, just paths. Some paths will eventually lead to an internal SCSI card but there is no special flag across all server lines. What you would need is a server hardware diagram for each model.

[A. Clay Stephenson]

... and on some models it's possible that a given disk could have an absolutely identical hardware path as on another otherwise identical machine and yet one be an internal disk and the other an external disk. As long as both the external disk and the internal disk were on the same SCSI bus and had the same target ID (SCSI ID) the hardware paths on the two machines would be identical and if the disk models were the same, ioscan would reveal no differences. It really comes down to knowing your hardware models and the devices attached to them. Actually, not being able to distinguish internal and external disks is a very good thing. It means that your HP-UX box can use a wide variety of disks made by different vendors and work well with them.