LinuxQuestions.org
Support LQ: Use code LQ3 and save $3 on Domain Registration
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 01-29-2014, 02:29 PM   #1
Preacherpj
LQ Newbie
 
Registered: Mar 2011
Posts: 20

Rep: Reputation: 0
Having trouble extracting data from DDS tapes on CENTOS 5.6


Hello -

I have a SCSI DDS tape deck and two DDS-3 tapes with data on them that I need to extract.

I know my connection to the deck is fine - I can eject, rewind, ffwd the tapes from the command line on the linux box. Additionally I know there is data on the tapes.

In the past when I've gotten tapes like this I've been able to pull data using

tar -xvf /dev/nst1

But when I try that now I get;

This does not look like a tar archive
Skipping to the next header
Error exit delayed from previous erros

I was able to determine block size on one of the tapes by using the following command (I'm having trouble getting the block size on the other tape)

dd if=/dev/nst1 of=testblock ibs=64k count=1

Which results in
0+1 records in
62+1 records out
32000 bytes (32k) copied

So I set the block size at 32000 bytes and re-run my tar command, but I still get nada from the tapes.

Would really appreciate any help/tips/guidance somebody out there could throw my way. I'm stuck.

Thanks
Ryan
 
Old 01-29-2014, 04:22 PM   #2
granth
Member
 
Registered: Jul 2004
Location: USA
Distribution: Slackware64
Posts: 211

Rep: Reputation: 50
Just curious, what's the output of "mt -f /dev/nst1 status"?

Try using dd to pull over the raw data. "dd if=/dev/nst1 ibs=32k of=~/image.dd".

Then analyze the data using normal methods. I'd use file, vi, testdisk, and photorec.
 
Old 01-30-2014, 10:59 AM   #3
Preacherpj
LQ Newbie
 
Registered: Mar 2011
Posts: 20

Original Poster
Rep: Reputation: 0
Quote:
Originally Posted by granth View Post
Just curious, what's the output of "mt -f /dev/nst1 status"?

Try using dd to pull over the raw data. "dd if=/dev/nst1 ibs=32k of=~/image.dd".

Then analyze the data using normal methods. I'd use file, vi, testdisk, and photorec.
mt -f /dev/nst1 status gives me;

SCSI 2 Tape drive:
File number=0, block number=5, partition=0
Tape Block size 32000 bytes, Density code 0x25 (DDS-3).
Soft error count since last status=0
General status bits on (1010000):
ONLINE IM_REP_EN

I ran the dd command you provided and it seemed to copy the data (755 mb) in total, but where does it put that data? I thought it would put it into the directory I'm currently in, but it didn't appear there...


Also, (and I appreciate the help) do you have any advice on the tape where I can't figure out the block size?

Thanks again!

Ryan
 
Old 01-30-2014, 11:14 AM   #4
Ser Olmy
Senior Member
 
Registered: Jan 2012
Distribution: Slackware
Posts: 2,412

Rep: Reputation: Disabled
You should be able to find the file image.dd in your home directory (~).

I would suggest running file ~/image.dd to see if it's a valid tar archive, perhaps compressed by gzip or bzip2.
 
Old 01-30-2014, 12:52 PM   #5
Preacherpj
LQ Newbie
 
Registered: Mar 2011
Posts: 20

Original Poster
Rep: Reputation: 0
Quote:
Originally Posted by Ser Olmy View Post
You should be able to find the file image.dd in your home directory (~).

I would suggest running file ~/image.dd to see if it's a valid tar archive, perhaps compressed by gzip or bzip2.

file ~/image.dd gives me

/root/image.dd: data
 
Old 01-30-2014, 01:27 PM   #6
granth
Member
 
Registered: Jul 2004
Location: USA
Distribution: Slackware64
Posts: 211

Rep: Reputation: 50
Quote:
Originally Posted by Preacherpj View Post
Also, (and I appreciate the help) do you have any advice on the tape where I can't figure out the block size?
Tape Block size 32000 bytes, Density code 0x25 (DDS-3).

^^^ From the mt command.


Since file was unable to tell you something useful. Try running the image through photorec and testdisk (I suggest reading the man pages first).

Code:
testdisk ~/image.dd
Code:
photorec ~/image.dd
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
need help reading data files from DDS-4 SCSI tape empulse Linux - Software 1 05-29-2009 05:47 PM
Using tapes for long term data storage. What software to use? Not Amanda. WojtekO Linux - Software 5 04-07-2009 03:10 AM
How to do a write/verify test on data tapes with a Storagetek L700e robotic library pyrotherm Linux - Software 1 04-27-2008 04:29 PM
IBM x3200 & Centos 4.4 with IBM 36/72GB DDS/5 choyyw@gmail.com Linux - Server 0 04-10-2007 02:30 AM
Deleting DDS 4 Tapes w/ Magnet ghight Linux - General 1 06-20-2003 12:04 PM


All times are GMT -5. The time now is 10:10 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration