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Redhat / CentOS 7: P5 unable to detect tape library
Posted by Andre Kuehnemund on 30 April 2015 20:08

This issue is apparently caused by a bug in RedHat / CentOS 7. Please see here:

https://bugzilla.redhat.com/show_bug.cgi?id=1193817

 

Customer:

 

"I just reinstalled a plain CentOS 7.

lsscsi see the drive and changer

[0:2:0:0] disk IBM ServeRAID M5014 2.13 /dev/sda
[0:2:1:0] disk IBM ServeRAID M5014 2.13 /dev/sdb
[1:0:0:0] disk External RAID 0 /dev/sdc
[2:0:0:0] cd/dvd IMM Virtual CD/DVD 0316 /dev/sr1
[3:0:0:0] cd/dvd MATSHITA DVD-ROM UJ890 WAA3 /dev/sr0
[7:0:0:0] tape HP Ultrium 6-SCSI 22GS /dev/st0
[7:0:0:1] mediumx STK SL150 0225 /dev/sch0
[8:0:0:0] tape HP Ultrium 6-SCSI 22GS /dev/st1

Which means the HBA is initialized and works.

PresStore cannot find my autoloader. I need help..."

 

Later...

 

"Fixed. It works. Turns out, the kernel module for scsi generic devices (sg) is not loaded by default anymore. lsmod revealed to me this annoyance.
A small text file in modules-load.d solved the whole thing. "

 

Here's the file:

 

#Module Load File for Generic SCSI devices mapping.

#By Jean-Sebastien Fortier jsfortier@pixcom.com
#Load sg module at boot
sg

 

Once the generic SCSI driver is loaded, this is what the output of the 'lsscsi -g command looks like.:

[root@backup02 /]# lsscsi -g
[0:2:0:0] disk IBM ServeRAID M5014 2.13 /dev/sda /dev/sg0
[0:2:1:0] disk IBM ServeRAID M5014 2.13 /dev/sdb /dev/sg1
[1:0:0:0] disk External RAID 0 /dev/sdc /dev/sg3
[2:0:0:0] tape HP Ultrium 6-SCSI 22GS /dev/st0 /dev/sg4
[2:0:0:1] mediumx STK SL150 0225 /dev/sch0 /dev/sg5
[3:0:0:0] cd/dvd MATSHITA DVD-ROM UJ890 WAA3 /dev/sr0 /dev/sg2
[7:0:0:0] tape HP Ultrium 6-SCSI 22GS /dev/st1 /dev/sg6

Notice the generic device names in the last column. If sg is not loaded you don’t have the last column.

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