Hi All,
I've been chasing down a problem with LUN masking on CentOS5/RHEL5 hosts
with QLogic HBA's for a few hours and seem to have got to an impass;
Any device (disks in my case) on Non-sequential LUN's are not registered
with the OS. This happens across various HBA models and kernel
versions. FYI, I'm currently running the latest qlogic qla2xxx drivers
(8.02.14.01) against kernel 2.6.18-128.1.10.el5 x86_64
For example if the LUN mask is set to 0,1,2,3 then all is OK and all
disks are configured. However, a mask of LUN 0 & 9 will not see the
disks on LUN 9. It appears the kernel stops scanning when there is a gap
in the LUN list.
I read in a number of places how to fix this issue, and indeed here:
http://filedownloads.qlogic.com/files/driver/48437/README_qla2xxx2-6U4.htm#BlacklistEntries
Apparently, I should be able to add a line to modprobe.conf that allows
sparse LUNs. So I followed the instructions and added
options scsi_mod dev_flags="SUN:CSM200_R:0x040" max_luns=20
and rebuilt initrd. This doesn't seem to work, as only LUN 0 is
configured by the OS despite LUN 9 also being unmasked.
I've also tried
options scsi_mod default_dev_flags=0x040 max_luns=20
in modprobe.conf with no luck
[root at host qlogic]# cat /proc/scsi/qla2xxx/1
<snip>
SCSI LUN Information:
(Id:Lun) * - indicates lun is not registered with the OS.
( 0: 0): Total reqs 144, Pending reqs 0, flags 0x2, Dflags 0x0, 0:0:83 00
( 0: 9): Total reqs 0, Pending reqs 0, flags 0x0*, Dflags 0x0, 0:0:83 00
[root at sgulfs-data1 ~]# cat /proc/scsi/scsi
Attached devices:
<snip>
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: SUN Model: CSM200_R Rev: 0616
Type: Direct-Access ANSI SCSI revision: 03
I can however do
echo "scsi add-single-device 1 0 0 9" > /proc/scsi/scsi
to enable LUN 9 and the disk is then configured.
I've ended up writing a script in rc.local to enable the LUN , scan LVM
and mount the file system which is not ideal.
Does anyone have any further insight into how I could get the OS to
enable these LUN's on boot thus eliminating the need for my doubtless
dirty script?
Cheers
Dan
