Reading HP 9000 DLT backup tape under Windows 2000

[Jean-Yves Rouffiac]

Hello,

I have been asked by a client to see whether it is possible to read data from old backup tapes written on an HP 9000 (which they no longer have), and export the data into some flat files under Windows.

I have no experience of the HP 9000, nor do I yet know what backup-program was used to write to the tapes - nothing quite like working without any information ;)

We do however have a DLT drive on one of our Win2000 boxes.

The tapes are Maxell DLTtape IV, but there is no indication as to their capacity.

Can anyone provide me with any pointers as to how to proceed. For example, is there a backup program that is provided as standard on the 9000? (I have seen OmniBack mentioned, but am not clear as to whether this is the correct application), is there a version available for Windows, etc, etc.

Any help would be very gratefully received.

[Vincent Farrugia]

Hello,

The success of this depends on with which application/program did they write the old backups. For instance, if they wrote them in tar format, it's different to fbackup, and it's different to Omniback.

So first question you need to ask them is, with which application/backup program did you write these old tapes?

HTH,
Vince

[Jean-Yves Rouffiac]

Hi Vince,

Thanks very much for the reply - I have asked the client for info on the backup program but as yet have had no reply (it's quite possible that they don't actually know).

Would it be possible to find this out from the Win2000 end? ie is there some software that will read the contents and give an idea of what filetype it is (maybe it would have a .tar file extension for example?).

I'm thinking along the lines of an Installable File System that could be started under Win2000 to read the HP 9000 format.

Thanks.

[Vladimir Vybiral · Accepted solution]

This reading from w2k end seems impossible to me, as the tape is formatted by the application that has been used for backup and the format differs app to app. The only possibility is really ask the customer again which application has been used for writing the tape. Or, find an UX box and a pro that would be able to mount the tape and read the contents somehow. This could be done on UNIX, but sorry, nothing like that on Win as far as I know.

[Vincent Fleming]

ANY unix-type box would do for reading the tape - there's so much more you can do with UNIX that you just can't do in windows.

Here's what I suggest if you haven't a unix-type box around - find a PC that they are not using, and a SCSI card, and borrow a DLT drive from one of their systems.

Then load FreeBSD or Linux on it (download for free). Poof! Instant unix-box. [hint: get the boot floppy, then you can load the O/S directly off their FTP servers.]

You can then use the 'dd' utility to pull the data off the tape. Then use the 'file' utility to find out what format it is.

# dd if=/dev/rmt/0m bs=32k of=/tmp/backup.file
# file /tmp/backup.file

It's very likely that you could unpack it on the UNIX box also, then ftp (or whatever) the data off to Windows.

Good luck,

Vince

[Jean-Yves Rouffiac]

Thanks guys, that's really helped. The good news is that I have found a colleague in another office who has a unix box with DLT tape drive, so I shall pass it on to him with the information that you have provided, and hopefully he'll be able to extract the data for me.

Again, thank-you :-)

[James Perry]

I have had to do a similar operation based on a case of tapes we had offsite, but it was not know which OS was used or what, if any, backup software was used. What I found helpful was to do a 'dd if= bs=1K | more' For most backups, I found the following file header/basic data formats. The file I am using for illustration is called test. If has a single line of "line 1"

CPIO:
0707070000010000021006660000000000030000010000000763612356400000500000000007testLine 1
0707070000010000021006660000000000030000010000000763612356400001300000000000TRAILER!!!0707070000010000021006660000000000030000010000000763612356400000500000000007testLine 1
0707070000010000021006660000000000030000010000000763612356400001300000000000TRAILER!!!0707070000010000021006660000000000030000010000000763612356400000500000000007testLine 1
070707000001000002100666000000000003000001000000076361235640000130000000001 blocks

Tar:
test000066600000000000003000000000070763612356400116310ustar00rootsys00000000000000Line 1

Fbackup:
ANSII standard label not yet implemented19456 1 /tmp
96 1 /tmp/test
7 1 /tmp/test/test
BOHBOTrpcbind.fileoutut9755.outBOHBOTLine 1

As for OmniBack, I am not familiar with it's backup format. What I do know is that most backup software uses Tar or CPIO as their basic backup internals. I know that this is the case for Veritas NetBackup and EMC's EDM software.

With respect to Veritas NetBackup (the software we use) there tape has the format that there is a tape header containing the barcode label as the first file and then each subsequent backup are placed as additional files.

The standard header (first file) looks something like this:
VOL1SU0391^A^F>^O^PM-3 ^A^DThIs Is A BP tApE hEaDer

Then it will contain a tar-based command string similar to the tar line above since NetBackup uses a modified version of GNU tar for their backups.

Also while importing the backups, you also want to make sure to use a non-rewinging device (/dev/rmt/0mn) for the data scan. The mt command on Unix will aid that process. What I would suggest is to do is to:
1. Mount the tape
2. mt -t /dev/rmt/0mn rew (seak to the beggining of the tape)
3. dd if=/dev/rmt/0mn bs=1k of=file1
Since the dd is on the non-rewinding device, it will be positioned at the next tape make on the tape if there is one.
4. Continue to do a dd if=/dev/rmt/0mn bs=1k of=fileX until you get an end of media error.

Alternately if you want to find out how many records or backups may be on the tape, you can do:
1. mt -t /dev/rmt/0mn rew
2. mt -t /dev/rmt/0mn status
3. mt -t /dev/rmt/0mn fsr 1 (forward seek 1 record)
4. Repeat 2-3 until no more records are found. I know from experience that after the last record it will take a LONG time for the fsr command to succeed since it will seek to the end of the media looking for that record.

Hope this helps.

[Jean-Yves Rouffiac]

That's great, many thanks for the info and step by step guide.
:)

I am hoping to have access to the unix box either tomorrow on on Monday, so fingers crossed!

[James Perry]

Glad to help. Let me know if you need more assistance.

[Vincent Fleming]

What did the 'file' command say about them?

[James Perry]

From looking at the header you supplied, this could be a variety of things. The 'VOL1<6-digit barcode> + data' can be about anything. This is an ANSI format for tapes and is usually used by backup software. What I would have you ask your team that read the tape headers is how they read them. The reason being that head and cat generate 2 different outputs for my Veritas tapes as shown below:

Cat /dev/rmt/0m:
VOL1SU0009
Head /dev/rmt/0m
VOL1SU0009/etc/passwddaemon:*:1:5::/:/sbin/sh
bin:*:2:2::/usr/bin:/sbin/sh
sys:*:3:3::/:
adm:*:4:4::/var/adm:/sbin/sh
uucp:*:5:3::/var/spool/uucppublic:/usr/lbin/uucp/uucico
lp:*:9:7::/var/spool/lp:/sbin/sh
nuucp:*:11:11::/var/spool/uucppublic:/usr/lbin/uucp/uucico
hpdb:*:27:1:ALLBASE:/:/sbin/sh
nobody:*:-2:-2::/:

While this is not exactly like what you have presented, it is similar.

From what I see of the tape header and Sybase, it looks most likely that a direct to tape Sybase dump utility of some form. This could be anything. I would have your team try to just cat the tape header and see if it will give more information. I know that on NetBackup there are a lot of special characters that head drops/ignores.

Also if these are Sybase backups, I do not think that the flat files will be a lot of use to you. From my days backing up Sybase, if 1 file is out of sync the entire database is usless. The numbers will be different on the header for the backups as that will tell the software specifics on the file being restored.

I would put in a call to Sybase and see if you could track down some support even if you have to pay a per-call charge for it. They should be beneficial in aiding you with at least what backup software may have been used. You can do this with Veritas also, but I think that Sybase would be a good place to start. They should be able to assist with the tape header. If you are lucky, you can get them to provide you with a 30-day trial of the software and possibly restore the data.

[Jean-Yves Rouffiac]

James, Vincent,

I forwarded your comments to my colleague and here are his replies:

"file" command:
- All files reported "data"

"cat" and head "commands"
- I tried "head /dev/nst0" and "cat /dev/nst0" and I got the same output as in the files I sent you apart from a few less spaces between text

Thanks,
Jean-Yves