topic Re: tar cannot open /dev/rmt/0mn in Operating System - HP-UX

tar cannot open /dev/rmt/0mn

Rohit Nagre — Fri, 04 Apr 2008 09:22:10 GMT

I have HP C1533A tape drive connect to hpux 11i system . It show in ioscan & I am aslo able to rewind tape by mt rew /dev/rmt/omn but whene i try to take backup using tar it given me error
tar : cannot open /dev/rmt/0mn.

ioscan outp file is attach.

please help me.

Re: tar cannot open /dev/rmt/0mn

Pete Randall — Fri, 04 Apr 2008 09:26:35 GMT

You said "mt rew /dev/rmt/omn" and you also mention "cannot open /dev/rmt/0mn". "omn" (letter o) is different from "0mn" (numeral zero). I have to wonder if you don't have a mis-named file in your /dev directory. Try running this:

find /dev -type f

If it returns anything, particularly your omn file, then you have a regular file in your /dev directory. Get rid of it, it does not belong. Then find out what the device file truly is for your tape drive and specify that in your tar command.

Pete

Re: tar cannot open /dev/rmt/0mn

MarkSyder — Fri, 04 Apr 2008 09:37:56 GMT

In addition to what Pete says, shouldn't tar be us8ing 0m rather than 0mn?

Mark Syder (like the drink but spelt different)

Re: tar cannot open /dev/rmt/0mn

Rohit Nagre — Fri, 04 Apr 2008 09:38:41 GMT

I tryed find /dev -type f
it come back to # prompt

Re: tar cannot open /dev/rmt/0mn

Pete Randall — Fri, 04 Apr 2008 09:50:43 GMT

Post output of "ioscan -fnCtape" please.

Pete

Re: tar cannot open /dev/rmt/0mn

Dennis Handly — Fri, 04 Apr 2008 09:59:53 GMT

>Pete: Post output of "ioscan -fnCtape" please.

That was in the attached file.

Re: tar cannot open /dev/rmt/0mn

Rohit Nagre — Fri, 04 Apr 2008 10:01:13 GMT

The out put ioscan as follows

# ioscan -fnC tape
Class I H/W Path Driver S/W State H/W Type Description
=======================================================================
tape 0 10/0/15/0.3.0 stape CLAIMED DEVICE HP C1533A
/dev/rmt/0m /dev/rmt/c2t3d0BESTn
/dev/rmt/0mb /dev/rmt/c2t3d0BESTnb
/dev/rmt/0mn /dev/rmt/c2t3d0DDS
/dev/rmt/0mnb /dev/rmt/c2t3d0DDSb
/dev/rmt/c2t3d0BEST /dev/rmt/c2t3d0DDSn
/dev/rmt/c2t3d0BESTb /dev/rmt/c2t3d0DDSnb

Re: tar cannot open /dev/rmt/0mn

Rohit Nagre — Fri, 04 Apr 2008 10:27:27 GMT

I am able to restore pravious backup file on same drive but only problem when i start take backup it gives error

# tar -cvf /dev/rmt/0m /etc/passwd
tar: cannot open /dev/rmt/0m
#

Re: tar cannot open /dev/rmt/0mn

MarkSyder — Fri, 04 Apr 2008 10:32:36 GMT

What reply do you get to:

tar tvf /dev/rmt/0m

Mark

Re: tar cannot open /dev/rmt/0mn

Pete Randall — Fri, 04 Apr 2008 10:37:22 GMT

Dennis> That was in the attached file.

Dennis, let me apologize in advance for all my future imperfections as well as those past. Please bear with me.

For your enlightenment, I rarely even bother to look at attachments because they are generally posted as Word documents. Being a HP-UX bigot and a Windoze hater, I browse on hp-ux and am unable to open the vast majority of attachments.

Pete

Re: tar cannot open /dev/rmt/0mn

Robert-Jan Goossens — Fri, 04 Apr 2008 10:37:31 GMT

Hi,

could you post the output of

# file /dev/rmt/0m
# ll /dev/rmt/0m

Regards,
Robert-Jan

Re: tar cannot open /dev/rmt/0mn

Rohit Nagre — Fri, 04 Apr 2008 10:38:28 GMT

Dear mark
it shows me list of file in tape .

Re: tar cannot open /dev/rmt/0mn

Rohit Nagre — Fri, 04 Apr 2008 10:43:44 GMT

output as follows
# file /dev/rmt/0m
/dev/rmt/0m: character special (205/143360)
# ll /dev/rmt/0m
crwxrwxrwx 2 bin bin 205 0x023000 Apr 5 05:31 /dev/rmt/0m

Re: tar cannot open /dev/rmt/0mn

MarkSyder — Fri, 04 Apr 2008 10:56:10 GMT

So it can read from a tape but not write to it. Is the tape write protected?

Mark

Re: tar cannot open /dev/rmt/0mn

Dennis Handly — Fri, 04 Apr 2008 12:36:15 GMT

>Pete: I rarely even bother to look at attachments because they are generally posted as Word documents.

In this case it was a .txt file. I later realized it was ioscan -funC tape if that made a difference.
One advantage of .txt attachments is that you do see the proper spacing.

>Being a HP-UX bigot, I browse on hp-ux

I too.

Re: tar cannot open /dev/rmt/0mn

AL_3001 — Sun, 06 Apr 2008 02:40:30 GMT

Hi Rohit,

As yu can read the content from the tape, and not write to it, the first thing that comes to my mind, just the may Mark has said "Is the tape write protected"? In most cases it is, so may be your problem is solved. If it is not write protected, let us know.

Cheers,
Ashish

Re: tar cannot open /dev/rmt/0mn

Akif_1 — Wed, 06 Aug 2008 08:20:38 GMT

Hi Rohit,

Hope this solution will solve your problem.

#ioscan -fnC tape

go to the /dev/rmt/ dir and delete all special files listed (be sure that you are in /dev/rmt/ directory).

Note: make sure about your tape device path after hitting above command:

#cd /dev/rmt
#rmsf -H 1/0/1/0/0/0.3.0 ..... path example

#ioscan -fnC tape

#insf -H 1/0/1/0/0/0.3.0 ....... path example

All the best

Re: tar cannot open /dev/rmt/0mn

sparcguy — Fri, 11 Jul 2014 15:30:50 GMT

I encountered this issue also and tried google and came across the thread, I tried all the abv suggested but nothing worked

Putting info here in case somebody googling for it.

my case was I was trying to do a solaris ufsdump from my sun server to a hpux server connect to a LTO3 tape drive.

ssh usgs0131_bk ufsdump 0ucf - /ist | dd bs=126b of=/dev/rmt/0mn

on the solaris server it kept saying cannot open /dev/rmt/0mn

So by elimination I tried troubleshoot on hpux server and tried using tar command and got the same error.

There's a useful command you need to know and that's mt, when I ran the mt command it showed it was write-protected. Basically I later learnt from another colleague that my LTO3 drive is not backward compatiable to LTO1 cartridge and that was the problem.

-- This is what you should see

root@USGS0127[/]#mt -f /dev/rmt/0mn stat
Drive: HP Ultrium 3-SCSI
Format:
Status: [41114400] BOT online compression immediate-report-mode
File: 0
Block: 0

-- I got the write protect message using LTO1 cartirdge even though it wasn't write protected

root@USGS0127[/]#mt -f /dev/rmt/0mn stat
Drive: HP Ultrium 3-SCSI
Format:
Status: [41114400] Write-Protected immediate-report-mode
File: 0
Block: 0

After I changed to the correct tape LTO3 or LTO2 it work

root@USGS0127[/]#ssh usgs0131_bk ufsdump 0ucf - /ist | dd bs=126b of=/dev/rmt/0mn

DUMP: Date of this level 0 dump: Fri Jul 11 23:18:06 2014
DUMP: Date of last level 0 dump: the epoch
DUMP: Dumping /dev/md/rdsk/d3 (usgs0131:/ist) to standard output.
DUMP: Mapping (Pass I) [regular files]
DUMP: Mapping (Pass II) [directories]
DUMP: Writing 63 Kilobyte records
DUMP: Estimated 5145510 blocks (2512.46MB).
DUMP: Dumping (Pass III) [directories]
DUMP: Dumping (Pass IV) [regular files]
DUMP: 5145460 blocks (2512.43MB) on 1 volume at 9080 KB/sec
DUMP: DUMP IS DONE
DUMP: Level 0 dump on Fri Jul 11 23:18:06 2014
0+346148 records in
0+346148 records out

root@USGS0127[/]#