Problem writing to remote tape device with fbackup

[Andrew Kaplan]

Hi there --

I am having a problem trying to write to a remote device within the FBackup utility in SAM on an HP-UX 10.20 system. The error message that I receive is the following:

fbackup(3301): could not open output file 132.183.20.143:/dev/rmt/0mnb

I have stopped and restarted the remote tape device, as well as rebooted the remote hp-ux 10.20 workstation. Additionally I am using a known-good tape, dlt, in the remote device.

Prior to my replacing the drive itself, is there anything else I can try to get backups to work? Thanks.

[Tim Nelson · Accepted solution]

Test tape on remote host first.
fbackup -i /some/files -f /dev/rmt/0m
(not sure why you are using no rewind device driver )

Then try manually using remote host device.
fbackup -i /some/files -f remotehost:/dev/rmt/0m

I believe you must properly configure remsh from serverA to serverB in order to use the rmt abilities.

I do not use remote tape devices as most attempts have been fruitless and a waste of time ( performance is extremely poor ).

[Andrew Kaplan]

Hi there --

Thanks for your reply. I ran an interactive backup on the workstation where the tape drive was locally attached, and the backup went by without a problem.

You mentioned the need for remsh to be configured properly. What file(s) and setting(s) do I need to modify in order for it to work? Thanks.

[Bill Hassell]

The remote server must allow the fbackup user to login without a password. I'll assume that you are root on the local system, so you'll need to create a file called .rhosts in the remote system's root home directory. This file must be 600 permission, owned by root and contains the IP address and hostname(s) of your local machine where you run fbackkup, something like this:

132.183.20.143
remhost
remhost.mydomain.com

The reason for several names and IP is to make sure that something matches your local machine's name as seen by the remote system. Once .rhosts is in place, test it with something like this:

remsh remhost date

It should return the date on the remote system. Now fbackup should work OK. Some notes about network backups:

- A 10 Mbit link is far too slow for tape backups. The minimum is 100 Mbit unless you are using very old reel-to-reel tape drives. For a remote DLT 8000, you may find the network is still too slow and overall throughput may be 1/5 to 1/10 normal speed due to data underruns.

- A network restore with frecover will not be able to do a high speed search for files (hours rather than minutes to recover a file).

- The remote system cannot be used to cold install your local system. You'll need a bootable HP-UX system running on the local system before you can recover any files from the tape. For a cold install (ie, a failed boot disk), you'll need to use Ignite/UX network backup which can indeed recover you local system onto a new disk.

[Andrew Kaplan]

Hi there --

Thanks for your help. Once I added the local host to the .rhosts file on the remote system, the backups succeeded.