tape drive device name changes on reboot

[Jeff Hoevenaar]

I am using IBM ULT3580-TD2 tape drives with the atdd driver. When the system reboots several of the device names (/dev/rmt/0m) will change. I will get several "NO_HW" outputs from ioscan and I have to go and remove them and reconfigure my TSM software to see the new device names.

Has anyone seen this happen and know what causes it?

Thanks.

[Pete Randall]

Jeff,

You can make the device file names whatever you want. See attached.


Pete

[Bill Hassell]

Do you mean that /dev/rmt/0m changes to /dev/rmt/mynewtape or do you mean that /dev/rmt/0m points to a non-existant tape drive (hint: lssf /dev/rmt/0m) and the the tape drive has a new hardware address and it's device file name is /dev/rmt/3m? If you change the drive address, or move it to another I/O card, it is a new device to the system. The proper way to move a device is to first delete it with rmsf, then during the reboot, change the address and/or I/O card and when the system comes back up, it will recreate the device. NO_HW means that a device used to exist at the specified address and has been removed without using rmsf.

Now the above is for a simple system, ie, one tape drive. If you have 4 tape drives, there is a possibility that the drive will get the next name in order, as in /dev/rmt/5m. No problem: Use rmsf to get rid of the 5m device files, then use insf with the -I option to selet the instance. An instance is the order of discovery as seen by ioscan.

And you can always rename device files. The name does not have to be 0m, it can ibm2 or TD2 or whatever you like. The connection between the real tape drive and the driver options is the major and minor number. The name is just a convenient way to sort out which major/minor combination you want to use. In all cases, you decode the devicefile name using lssf.

[Jeff Hoevenaar]

I found this in the rc.log. Looks like each tape device is being reconfigured on a reboot and perhaps some files are locked so it doesn't work properlly. I have 16 tape drives. Does this make sense to anyone?

Initialize loadable modules
Output from "/sbin/rc1.d/S112kminit start":
----------------------------
* All configured modules are registered successfully.
* Newly built modules are initialized successfully.
insf: Installing special files for stape instance 1 address 0/4/0/0.98.12.255.1.3.0
insf: Installing special files for stape instance 2 address 0/4/0/0.98.14.255.1.3.0
* Module atdd is loaded successfully.
* Module acdd is loaded successfully.

NOTE: Module status

Name ID Status Type
=====================================================
krm 1 UNLOADED WSIO
atdd 2 LOADED WSIO
acdd 3 LOADED WSIO

Configure GES driver for IBM Tape and Library Devices
Output from "/sbin/rc3.d/S500atdd_cfg start":
----------------------------

ioscan: libIO error from io_insert_node: Node already exists or parameter error detected.
tape 1 0/4/0/0.98.12.255.1.3.0 stape CLAIMED DEVICE IBM ULT3580-TD2
rmsf: Unable to lock /etc/ioconfig - : Cannot lock /etc/ioconfig file.
ioscan: libIO error from io_insert_node: Node already exists or parameter error detected.
tape 2 0/4/0/0.98.14.255.1.3.0 stape CLAIMED DEVICE IBM ULT3580-TD2
rmsf: Unable to lock /etc/ioconfig - : Cannot lock /etc/ioconfig file.