Max Lun

[Dennis Rhodes]

I am a little bit confused about the maximum number of lun's supported by Aix the first install guide had no limitations but the very latest one suggests that the XP256 supports a maximum of 32 lun's per FC-port( Page 14 of the AIX Install guide). Can you please get some clarity on this because something like 56 Lun's on a single FC port at BOE, these limitations also suggest a maximum of 512 Lun's per XP frame, using open 0 lun's this equates to 3.6Tb max.

[Mike Naime]

IBM AIX using Securepath to access a COMPAQ STORAGEWORKS SAN:

The older versions of securepath used to suport up to 16 LUNS per Storage subsystem, and the storage subsystem had to be setup for SCSI-2 mode of operation.
I do not remember the total number of LUNS per HBA.

Today, I can present up to 32 LUNS per storage subsystem in SCSI-3 mode. This is a Limit of the HBA drivers, not the storage system. There is also a Limit on how many total LUNS that the HBA itself will see from all storage systems.

I have AIX, VMS, and W2K sharing storage on the same controller on one of my HSG's.

[Dennis Rhodes]

I specifically need info for an XP256.Thanx for your prompt response.

[Mike Naime]

Dennis:


I'm not sure that you understood my last post.

Your Limiting factor here is going to be the amount of LUNS that the AIX HBA will see, not the # of LUNS that the Storage controller can present.
Your storage controller does not matter here. XP256, XP1024, EVA, HSG... Etc. Your AIX HBA will still only see 32 LUNS from any of these devices. You might be able to present 512 LUNS from the XP256, but the AIX system will only see the first 32!