HP StoreEver Tape Libraries Failover User Guide (5697-3323, June 2014)

Memory dump setup
To configure Windows to produce a memory dump, see http://support.microsoft.com/kb/254649.
The configuration process includes specifying the name and location for the dump file, as well as
the type of the dump. The type should be a kernel memory dump, although the larger complete
memory dump is acceptable. Do not select the small memory dump. If a bug check occurs, then
after a reboot the file can be retrieved and sent for diagnosis.
Driver debug dump setup
Generating a driver debug dump log file requires installing checked drivers and the DebugView
application. This is an advanced technique. For instructions, see “Windows driver debug dump
setup” (page 63).
Bug checks
Following a bug check, restart the system and retrieve the kernel dump for transmission to HP. If
driver debug dumps were enabled, then retrieve the driver debug log file for transmission to HP.
Hangs
If the system hangs, the system can be configured to allow forcing a system crash from the keyboard.
This is explained in http://msdn.microsoft.com/en-us/library/ff545499(v=VS.85).aspx.
If the system hangs after configuring, force the crash and reboot. Then retrieve the kernel dump
for transmission to HP.
Linux logs and troubleshooting tools
Report cached reservation information
The Linux advanced path failover driver tracks reservation information for tape libraries to enable
rebuilding the reservations if a failure requires changing the drive that is hosting the library control
path. These commands dump the reservation information cache buffers to the /var/log/messages
file and the console.
Legacy reservations:
echo legacy > /sys/class/pfo/pfo4/ctrl
Persistent reservations:
echo persistent > /sys/class/pfo/pfo4/ctrl
Prevent allow medium removal conditions:
echo prevent > /sys/class/pfo/pfo4/ctrl
Debug output control
You can control the level of debug messages being sent to the console.
The default output level is minimum.
To minimize the level of debug messages:
echo 0x0000 > /sys/bus/scsi/drivers/pfo/debug_flag
To maximize the level of debug messages:
echo 0xffff > /sys/bus/scsi/drivers/pfo/debug_flag
NOTE: Increased debug logging will affect performance.
The definition of all of the bits in the value is beyond the scope of this document.
Linux logs and troubleshooting tools 59