I have a MSL6060 Library with 2 LTO2 tape drives and I have been having the following issue for the last week or so. The tape loads the backup tries to begin but can not find the drive, it unloads and loads the tape and does an autodiscovery. Eventually it finds the device and does the backup successfully. This loading and unloading and discovery burns up about 45 minutes for each backup that uses this device. See below thread. I also have a devbra -dev and an ioscan -fnC listed and have hilited the device.
Warning] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:23:09 AM
The device "SAN_Lib_2_hem_os" could not be opened("Device could not be accessed")
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:23:09 AM
Starting the device path discovery process.
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:23:14 AM
A new path(s) "/dev/rtape/tape11_BESTn" found for device "SAN_Lib_2_hem_os" and stored.
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:23:14 AM
Device path discovery process finished.
[Major] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:30:05 AM
[90:54] /dev/rtape/tape11_BESTn
Cannot open device ([6] No such device or address)
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:30:05 AM
By: UMA@ironwood.it.uwosh.edu@/dev/rchgr/autoch2
Unloading medium to slot 38 from device /dev/rtape/tape11_BESTn
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:30:23 AM
By: UMA@ironwood.it.uwosh.edu@/dev/rchgr/autoch2
Loading medium from slot 38 to device /dev/rtape/tape11_BESTn
[Warning] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:37:07 AM
The device "SAN_Lib_2_hem_os" could not be opened("Device could not be accessed")
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:37:07 AM
Starting the device path discovery process.
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:37:13 AM
A new path(s) "/dev/rtape/tape11_BESTn" found for device "SAN_Lib_2_hem_os" and stored.
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:37:13 AM
Device path discovery process finished.
[Major] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:44:18 AM
[90:54] /dev/rtape/tape11_BESTn
Cannot open device ([6] No such device or address)
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:44:18 AM
By: UMA@ironwood.it.uwosh.edu@/dev/rchgr/autoch2
Unloading medium to slot 38 from device /dev/rtape/tape11_BESTn
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:44:36 AM
By: UMA@ironwood.it.uwosh.edu@/dev/rchgr/autoch2
Loading medium from slot 38 to device /dev/rtape/tape11_BESTn
[Warning] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:52:00 AM
The device "SAN_Lib_2_hem_os" could not be opened("Device could not be accessed")
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:52:00 AM
Starting the device path discovery process.
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:52:06 AM
A new path(s) "/dev/rtape/tape11_BESTn" found for device "SAN_Lib_2_hem_os" and stored.
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:52:06 AM
Device path discovery process finished.
[Major] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:59:46 AM
[90:54] /dev/rtape/tape11_BESTn
Cannot open device ([6] No such device or address)
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 2:59:46 AM
By: UMA@ironwood.it.uwosh.edu@/dev/rchgr/autoch2
Unloading medium to slot 38 from device /dev/rtape/tape11_BESTn
[Normal] From: BMA@hemlock.it.uwosh.edu "SAN_Lib_2_hem_os" Time: 2/19/16 3:00:04 AM
By: UMA@ironwood.it.uwosh.edu@/dev/rchgr/autoch2
Loading medium from slot 38 to device /dev/rtape/tape11_BESTn
# ./devbra -dev
Tape HP:Ultrium 3-SCSI Path: "/dev/rtape/tape9_BESTn" SN: "HU108275AA"
Description: HP LTO3 Drive
Revision: G65W Device type: lto [13] Flags: 0x0001
Tape HP:C7438A Path: "/dev/rtape/tape10_BESTn" SN: "MXP40700N3"
Description: HP StorageWorks DAT 72 Drive
Revision: ZPBC Device type: 4mm [1] Flags: 0x0001
Tape HP:Ultrium 2-SCSI Path: "/dev/rtape/tape11_BESTn" SN: "MXP1H0429K"
Description: HP LTO drive
Revision: F6AW Device type: lto [13] Flags: 0x0001
Tape HP:Ultrium 2-SCSI Path: "/dev/rtape/tape12_BESTn" SN: "HUP5C04AJF"
Description: HP LTO drive
Revision: F6AW Device type: lto [13] Flags: 0x0001
Tape HP:Ultrium 3-SCSI Path: "/dev/rtape/tape17_BESTn" SN: "HUE13287CN"
Description: HP LTO3 Drive
Revision: G65W Device type: lto [13] Flags: 0x0001
# ioscan -fnC tape
Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
tape 15 0/2/1/0.42.1.255.0.0.0 stape CLAIMED DEVICE HP Ultrium 3-SCSI
/dev/rmt/15m /dev/rmt/15mn /dev/rmt/c6t0d0BEST /dev/rmt/c6t0d0BESTn
/dev/rmt/15mb /dev/rmt/15mnb /dev/rmt/c6t0d0BESTb /dev/rmt/c6t0d0BESTnb
tape 16 0/2/1/0.42.1.255.0.0.1 stape CLAIMED DEVICE HP Ultrium 3-SCSI
/dev/rmt/16m /dev/rmt/16mn /dev/rmt/c6t0d1BEST /dev/rmt/c6t0d1BESTn
/dev/rmt/16mb /dev/rmt/16mnb /dev/rmt/c6t0d1BESTb /dev/rmt/c6t0d1BESTnb
tape 13 0/2/1/0.42.5.255.0.0.0 stape CLAIMED DEVICE HP Ultrium 2-SCSI
/dev/rmt/13m /dev/rmt/13mn /dev/rmt/c4t0d0BEST /dev/rmt/c4t0d0BESTn
/dev/rmt/13mb /dev/rmt/13mnb /dev/rmt/c4t0d0BESTb /dev/rmt/c4t0d0BESTnb
tape 14 0/2/1/0.42.5.255.0.0.1 stape CLAIMED DEVICE HP Ultrium 2-SCSI
/dev/rmt/14m /dev/rmt/14mn /dev/rmt/c4t0d1BEST /dev/rmt/c4t0d1BESTn
/dev/rmt/14mb /dev/rmt/14mnb /dev/rmt/c4t0d1BESTb /dev/rmt/c4t0d1BESTnb
tape 0 0/3/1/1.2.0 stape CLAIMED DEVICE HP C7438A
/dev/rmt/0m /dev/rmt/0mn /dev/rmt/c2t2d0BEST /dev/rmt/c2t2d0BESTn
/dev/rmt/0mb /dev/rmt/0mnb /dev/rmt/c2t2d0BESTb /dev/rmt/c2t2d0BESTnb