kern/134488: [SCSI] MPT SCSI driver probes max. 8 LUNs per device

Michel Bouissou michel.bouissou at
Tue May 12 14:50:01 UTC 2009

>Number:         134488
>Category:       kern
>Synopsis:       [SCSI] MPT SCSI driver probes max. 8 LUNs per device
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue May 12 14:50:00 UTC 2009
>Originator:     Michel Bouissou
>Release:        7.2
The MPT SCSI driver is only able to scan up to 8 LUNs (0-7) per SCSI device, which is far too few for some SCSI disks enclosures.

This issue had already been discussed in about a year ago, but it seems not to have been fixed even though the fix is easy.


The highest LUN number that MPT will scan is hardcoded in dev/mpt/mpt_cam.c around line 3605 :

cpi->max_lun = 7;

Replacing this "7" with the number you want solves the issue (I used 32 for my needs).

But this necessitates the sysadmin to patch and recompile the kernel... Would be nice if this could default to a more sensible value than "8"...


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