cpio on hp-ux 10.20

[Tammy Liang]

I tried to restore a cpio file from tape with command " cpio -idcmv < /dev/rmt/0m". I got "End of Volume. If you want to go on, type device/file name when ready"
What is "End ov Volume" mean?
I enter "/dev/rmt/0m" and see the size of restored file increased.
What's the cpio command for listing the content of the tape drive?

Thanks for any reply.

Tammy

[Pete Randall]

You might need to rewind the tape first:

mt rew

It sounds to me like you're at the end of the tape.


Pete

[Tammy Liang]

I did not rewind the tape,just enter the tape device file /dev/rmt/0m. Does cpio rewind on its own?
tks

[Johnson Punniyalingam]

Hi Tammy,

>>> I did not rewind the tape,just enter the tape device file /dev/rmt/0m. Does cpio rewind on its own? <<

NO, It doesn't rewind on its own. we have to rewind , please follow the rewind command

# mt -f /dev/rmt/0mn status
(will show you tape is ONLINE)

# mt -f /dev/rmt/0mn rewind

Than try with cpio command for Listing .. :)

Thanks,
Johnson

[Dennis Handly · Accepted solution]

>What is "End of Volume" mean?

It means what it says. You are at the end of the tape reel. You need to "mount" another.

>I enter "/dev/rmt/0m"

I assume you first ejected the tape and put the next volume there?

>What's the cpio command for listing the content of the tape drive?

I suggest you give up on tar(1) and cpio(1) and only use pax(1).
You simply use:
pax -tv -f /dev/rmt/0m

>Pete: You might need to rewind the tape first

Are you suggesting the tape was first written and now read, without rewinding?

[Tammy Liang]

All,
Thanks for the reply.I did not eject/rewind the tape. I just entered the same device name and cpio append the file to the same file name. Looks like cpio handle the rewind part.

Tammy

[Tammy Liang]

All,
How can I setup block size with cpio to restore file?
I'm using "cpio idcmv < /dev/rmt/0m".

Thanks.

[OldSchool]

as far as I know, you can't. it is what it is.

man "cpio" seems to indicate that it deals in 512 byte blocks.

one wonders why you ask

[Dennis Handly]

>How can I setup block size with cpio to restore file? I'm using "cpio idcmv < /dev/rmt/0m".

Do you know what the block size is? You have N options, use -B for 5120 bytes, use a pipe with dd to reblock or good old pax(1).

>OldSchool: as far as I know, you can't. it is what it is. one wonders why you ask

See above. It would also be helpful to know how it was written to tape?

Also, as I mentioned, pax(1) will magically figure out how to read your tape. See:
-b blocking Blocking is automatically determined on input.

[Tammy Liang]

I don't know how the file cpio to tape.
It was old tape that we need to restore for
oracle data. After restore the file
with cpio, oracle import failed. I restored
the files from 2 different tapes, and imp failed on both of export files.
So the bottom line is you can not setup block size for cpio when restore from the tape drive.

[OldSchool]

"So the bottom line is you can not setup block size for cpio when restore from the tape drive."

see Dennis' reply above. He notes -B will reset the block size to 5120.

better yet, he suggested (twice) that you use "pax" instead, which will sort out the blocking correctly.

having hit "End of Volume" and continued on using the same tape w/o rewind makes me wonder how the tape was produced in the first place.

[Tammy Liang]

So I can pax to restore the file that created via cpio? If so, what's the command?

Can you provide the cpio commands that I can use with -B and dd for getting cpio file from /dev/rmt/0m?

Tks.

[Dennis Handly]

>So I can pax to restore the file that created via cpio?

Yes: pax -rv -f /dev/rmt/0m

>Can you provide the cpio commands that I can use with -B and dd for getting cpio file from /dev/rmt/0m?

-B works only if you used -B to write it.

Using dd(1) is completely separate more complicated approach.
Some threads:
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1281104
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1163073
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1252713
http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1229193

[James R. Ferguson]

Hi Tammy:

I would add, for your further information, that 'cpio' cannot archive 'largefiles' (files > 2GB).

With 'pax', when Using '-x cpio' or '-x ustar' files up to 8GB can be archived.

In 11.31 or in 11.23 with the PAX_ENH product installed, 'pax' can archive files larger than 8GB.

HP is making 'pax' a defacto standard for HP-UX and is in fact, deprecated (the extremely useful but proprietary) 'fbackup' utility.

Regards!

...JRF...

[James R. Ferguson]

Hi (again) Tammy:

Oh, the above is just another reason to move from the unsupported, ancient 10.20 release to at least 11.11.

I keep missing the fact that you noted your release as 10.20.

Regards!

...JRF...

[Tammy Liang]

Thanks all. We moved from hp-ux to redhat linux. For this particular case, I need to restore file that was created years ago on hp-ux 10.20 with cpio command to get some oracle data out...
I will try the "pax" command.

Tks.

Tammy

[Tammy Liang]

All, the pax does work. file was restored and
imported to database.

Tks for all reply.