topic Re: Device Files in Operating System - HP-UX

Device Files

Danny Baldono — Tue, 05 Jul 2005 00:38:04 GMT

I am migrating from N-Class (11i) to RP7420 (11i). My backup scripts on my N-Class using
specific device files (/dev/rmt/9m). On my new
RP7420 for sure will create new device files
(not /dev/rmt/9m). How can I run my scripts
on my new machine. I don't know about scripting.

Re: Device Files

Mahesh Kumar Malik — Tue, 05 Jul 2005 01:37:45 GMT

Hi Danny

From ioscan find out device file for tape drive in rp7420 and then edit the script to reflect new device file.

Regards
Mahesh

Re: Device Files

Sudeesh — Tue, 05 Jul 2005 01:41:02 GMT

Hmm .. it will be quite easy if you prefer to vi and modify your script to handle the newe device files. Though I understand from your post that you dont want to disturb the existing scripts.

Other option you can use is to create a link to new device file from /dev/rmt/9m.

ln -s /dev/rmt/0m /dev/rmt/9m

Hope this helps

Sudeesh

Re: Device Files

Leif Halvarsson_2 — Tue, 05 Jul 2005 02:45:03 GMT

Hi,

Or, create a new devicefile with the old name, if you know the new devicefile it is easy.

ll /dev/rmt/0m
crw-rw-rw- 2 bin bin 205 0x051000 Mar 18 15:51 /dev/rmt/0m

mknod /dev/rmt/9m c 205 0x051000

ll /dev/rmt/9m

crw-rw-rw- 2 bin bin 205 0x051000 Mar 18 15:51 /dev/rmt/9m

Re: Device Files

Danny Baldono — Wed, 06 Jul 2005 03:42:02 GMT

I created two additional device files 9m and c10t13d1BEST (the actual device file on my backup script). I've notice that there are three 0x30000 (see attached) entries.
Those are 0m, 9m, c10t13d1BEST. I tried to
read and write on these three using these device file and all are OK. Since these three have identical 0x30000 is this normal,
or will create problem?

Re: Device Files

Leif Halvarsson_2 — Wed, 06 Jul 2005 03:56:55 GMT

Hi,
Yes, it is normal to have more then one devicefile pointing at the same adress. It is not any problem if you don't thy to use two files concurrently.

Re: Device Files

Cheryl Griffin — Wed, 06 Jul 2005 06:38:20 GMT

Danny,
The difference between the m and the BEST devices are explained on the mt(7) man page
http://docs.hp.com/en/B2355-90697/mt.7.html

If the hardware can handle has the ability, and a BEST device were used, it could change the compression (density, format).

If the hardware can't handle it, using 9m would be the same as using the BEST device.