removing cXtXd0 and how does HPUX handle it

[Chris Fadrowski]

this question kind of piggy backs my last one. I have figured out the mapping from my Hitachi back to my HPUX server as far as cXtXdX goes, but the only disk i can move is at address c19t0d0. Now, i am wondering how HPUX handles not having the "d0". Meaning the first disk it would see would be c19t0d1. Can HPUX handle that or does it have to have a d0 in order for it to find disks at boot up? This may sound like a funny question, but i remember some OS's not handling that very well. thanks.

[Steven E. Protter]

HP-UX just handles it. It will show up either on ioscan or after the system is booted back up after the install.

To quote Pete Randall: HP-UX is an Industrial Strength Enterprise Operating System.

Such operating systems handle such things.

So long as there is not a SCSI address conflict or termination problem, you should be all set.



SEP

[Eugeny Brychkov]

Sometimes when there's no LUN0 for the target (for example, I saw it for some FC disk arrays) HPUX creates 'phantom' LUN0 and lists it in ioscan. If you will do diskinfo on this LUN, it will show size=0
Eugeny

[Caesar_3]

Hello!

HP handel this in the code of kernel and devices if you really want to know how it
work, this you could know only from developers of HPUX.

Caesar

[James Murtagh]

Hi Chris,

The kernel patch PHKL_21607 (SCSI IO) was introduced in HPUX 11.00 to take care of this exact situation. The functionality was built in to 11i I believe. Basically the OS scans the whole bus instead of just the consecutive luns starting at 0. There was no great enhancement (in the addressing side) to get this functionality - the reason it was excluded originally was due to performance reasons. The enhancement in ioscan performance led to this feature being introduced.

Regards,

James.