number of LUNs

[Charles THISE]

Hi,

How much LUNs i can attach to a A4800A scsi adapter ?

And how much on a fc adapter A5158A ?

i use hpux 11.00.

In advance i thank you.

Charles.

[Ian Dennison_1]

Off the top of my head,

15 LUNS is the addressing limit for SCSI devices (IDs 0 - 6, 8 - 15)

Fibre LUNS are virtually unlimited (in the millions), but there may be a limit on HP-UX or the switching equipment (we are limited here to 256 LUNs per channel at the switch).

Share and Enjoy! Ian

[Charles THISE]

Ok, many thanks to you.

But my question is how many luns one scsi id can support ?

In AIX, one scsi id can support up to 32 luns.
Also, i can connect up to 480 disks to one scsi adapter (15 IDs * 32 Luns).

thanks again.

Charles.

[Gerrit Beyken · Accepted solution]

Hi Charles,

if you have a Wide SCSI-Controller you have 15 SCSI-IDs which can be used ( 16 - 1ID for Controller) and a Narraw Controller has 7 Ids which you can use.
Each SCSI-ID can hold up to 8 Luns (0-7).
So for a Wide-SCSI-Controller you have 15*8=120 Devices.

Best regards

Gerrit Beyken

[Leif Halvarsson_2]

Hi


The number of disks depends on the number of SCSI-channels on the RAID-controller, if wide SCSI 15*number_of_channels.

You can divide one disk in several LUNs or assign several disks to one LUN. The number of LUNs depends of the RAID controller 32 or 64 is common with low-end controllers but some controllers support more then 1000 LUNs.

[Victor BERRIDGE]

>And how much on a fc adapter A5158A ?

This depends more on what kind of bay ou attach your box, for instance behind a HDS9980V /XP1024 the number of LUNs are per fibre:
Solaris : 256/fibre
HP-UX : 256/fibre
AIX : 128/fibre
NT/W2K : 32/fibre


So the question is are you sharing the fibres via a switch or have you fibres dedicated to a box...

All the best
Victor