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2 tapes in Cluster HP Tru64 UNIX V5.1B

Rodrigo Pineda
Occasional Visitor

2 tapes in Cluster HP Tru64 UNIX V5.1B

Ok First
We have 3 machines with HP Tru64 UNIX V5.1B in cluster.

Machine A have a tape
Machine C have another tape.

Both tapes are the same. When i scan new hardware scsi in Machine A the tape is detected in tape0
(hwmgr scan scsi)
When i scan en Machine C, the tape is detected as tape0.
But the machines are in cluster, when i rename the tape0 as tape1 in machine C, the machine A rename too the tape0 to tape1.

How i can force the detection hardware tape in Machine C and make a tape1 for not touch the devices tape0?

Both machines are using the same /dev , that means if i do something will be doit in both machines.

I need to have tape0 and tape1, so if i am in Machine A i need to access to the two tapes.

Excuse my english

6 REPLIES
Mark Poeschl_2
Honored Contributor

Re: 2 tapes in Cluster HP Tru64 UNIX V5.1B

Are these direct-attached tape drives? If so you can't share them across cluster members. Fibre-channel attached tape drives can be shared since the whole SAN fabric(s) are available to all cluster members.
Matt Palmer_2
Respected Contributor

Re: 2 tapes in Cluster HP Tru64 UNIX V5.1B

Hi,

not sure if you are needing to do this just because you need to backup, but you could try the following, if you want to access drives from either machine.

if you need to be able to remotely access a tape device attached to either machine, you can use commands like rdump to backup data from one machine using the tape drive of another:

rdump -0f MachineA:/dev/ntape/tape0 /dev/rz11c

you should get output like:
Dumping /dev/rrz11c (/filesys_name) to MachineA:/dev/ntape/tape0

This will backup a local filesys on MachineC to the drive on MachineA.

hope that helps.

regards

Matt
Rodrigo Pineda
Occasional Visitor

Re: 2 tapes in Cluster HP Tru64 UNIX V5.1B

Ok:

If i install (hwmgr scan scsi) in one machine (Machina A for example), the unit is installed in tape0 and can be used be MachineA or MachineC.

Then i install another tape in the other machine (Machine C and is the SAME model device ) and this is installed in the same tape number tape0.

The result is MachineA view is own tape0, and MachineC view is own tape0.....
Rob Leadbeater
Honored Contributor

Re: 2 tapes in Cluster HP Tru64 UNIX V5.1B

Hi,

Please can you post the output of

# hwmgr show scsi -full
and
# hwmgr view device

from each node, so that we can see exactly what's happening.

Cheers,

Rob
Rodrigo Pineda
Occasional Visitor

Re: 2 tapes in Cluster HP Tru64 UNIX V5.1B

MACHINE A , with a tape scsi One


SCSI DEVICE DEVICE DRIVER NUM DEVICE FIRST
HWID: DEVICEID HOSTNAME TYPE SUBTYPE OWNER PATH FILE VALID PATH
-------------------------------------------------------------------------
341: 25 chbpa tape none 0 1 tape1 [4/6/0]

WWID:02000008:5000-8780-0000-0000


BUS TARGET LUN PATH STATE
---------------------------------
4 6 0 valid




HWID: Device Name Mfg Model Location
------------------------------------------------------------------------------
3: /dev/dmapi/dmapi
319: /dev/random
320: /dev/urandom
327: /dev/disk/cdrom4c HL-DT-ST CD-RW GCE-8320B bus-1-targ-0-lun-0
341: /dev/ntape/tape1 QUANTUM DLT VS160 bus-4-targ-6-lun-0


MACHINE C and tape two:



SCSI DEVICE DEVICE DRIVER NUM DEVICE FIRST
HWID: DEVICEID HOSTNAME TYPE SUBTYPE OWNER PATH FILE VALID PATH
-------------------------------------------------------------------------
341: 23 chbpc tape none 0 1 tape1 [3/6/0]

WWID:02000008:5000-8780-0000-0000


BUS TARGET LUN PATH STATE
---------------------------------
3 6 0 valid



HWID: Device Name Mfg Model Location
------------------------------------------------------------------------------
3: /dev/dmapi/dmapi
5: /dev/kevm
67: /dev/disk/cdrom0c HL-DT-ST RW/DVD GCC-H20N bus-0-targ-0-lun-0
69: /dev/random
70: /dev/urandom
341: /dev/ntape/tape1 QUANTUM DLT VS160 bus-3-targ-6-lun-0



How can i force the detection of the tape with another device name... like a tape2.

when i remove with "hwmgr delete scsi -did " in one machine, the devices is deleted from both server because they have the same name device /dev/tape/tape1.
DCBrown
Frequent Advisor

Re: 2 tapes in Cluster HP Tru64 UNIX V5.1B


Tape 0: WWID:02000008:5000-8780-0000-0000
Tape 1: WWID:02000008:5000-8780-0000-0000
^^^^^^^^^^^^^^^^^^^
same world wide id!?

You may know these are two different physical tapes, but both tapes are providing the same world-wide-identifier for both tapes. WWIDs, per spec, kind of need to be world wide unique in order to work. In this case the system sees these two as the same because when it interrogates them it gets back from both my unique name is (the id above).

There is a method within the DDR entry for the device to change/force the use of a less unique identifier - typically the serial number is chosen. If the manfacturer didn't provide a ddr entry for Tru64 you can try and make one yourself modeled on another tape.... or you can buy different tapes that work correctly.

Its been a while since I worked on T64, so I don't remember the magic in the DDR to change to the alternate wwid. I'm sure a search of the web will turn it up for you though.