topic Re: Directory Checksum Error in Operating System - HP-UX

Directory Checksum Error

Prathap_1 — Wed, 27 Feb 2002 21:01:12 GMT

Hi
In addition to yesterdays question, I am still facing the problem with reading the tapes. I am getting an error called Directory Checksum Error and Tar: Tape Blocksize Error While attempting to read the tapes. I followed the solution given by Shiju for checking the backup type performed while taking the backups using the 'dd' method. It is returning the file type as English. How can I proceed reading the tape. Sometimes it is giving the error called Tar:blocksize=2 Directory Checksum Error while reading the tape using Tar command. Can anybody help me out in this issue.

Thanks
Prathap.

Re: Directory Checksum Error

harry d brown jr — Wed, 27 Feb 2002 21:11:27 GMT

Prathap,

try this:

tar -tvb2 -f /dev/rmt/om

live free or die
harry

Re: Directory Checksum Error

Prathap_1 — Wed, 27 Feb 2002 21:30:54 GMT

Hi Harry
I have tried tar -tvb2 -f /dev/rmt/1m. It is giving the message called Invalid Blocksize (Max 64).

Thanks
Prathap.

Re: Directory Checksum Error

Patrick Wallek — Wed, 27 Feb 2002 21:33:46 GMT

What EXACT command was used to create the tape? What EXACT command are using to produce the error?

Re: Directory Checksum Error

Prathap_1 — Wed, 27 Feb 2002 21:39:11 GMT

Hi Patrick
I don't know the backup method used for taking the backups. I am assuming that the backup has performed with tar, so I am trying with tar -tvf /dev/rmt/1m to read the contents from the tape. While reading the tape contents with tar, I am getting the error called 'Directrory Checksum Error' and 'Tar: Tape Blocksize Error'.

Thanks
Prathap.

Re: Directory Checksum Error

Patrick Wallek — Wed, 27 Feb 2002 21:44:33 GMT

Sounds to me like they weren't created with tar.

What happens if you try:

# frecover -f /dev/rmt/?m -I /tmp/some_filename

If this is an fbackup tape, the index will be extracted and written to /tmp/some_filename.

or you could try:

# frecover -f /dev/rmt/?m -N

This way the whole tape will be read and you will see everything that's on the tape, but NOTHING will be recovered.

Re: Directory Checksum Error

Helen French — Wed, 27 Feb 2002 21:46:32 GMT

Hi Prathap,

Normally when you use the command:

# dd if=/dev/rmt/ of=/tmp/tapetest bs=1K count=2

# file /tmp/tapetest

It will return the answer that the file is a cpio or tar archive. This is what I' ve mentioned before.

Also did you try other commands ?

# /bin/cpio -ictvB < /dev/rmt/
# frecover
# pax

HTH,
Shiju

Re: Directory Checksum Error

A. Clay Stephenson — Wed, 27 Feb 2002 21:49:53 GMT

Hi:

Tar can normally determine the blocksize and thus I suspect that this is not a tar OR has been recorded in a byte-swapped format. I suggest that you do this:

dd if=/dev/rmt/0m (or whatever) bs=512 count=3 | od -Ad -tc -v > /tmp/myfile.

This will dump 3 512-byte blocks in a human-readable format to /tmp/myfile. If you will then attach /tmp/myfile, I think someone will recognize the tape format (or lack thereof).

Regards, Clay

Re: Directory Checksum Error

Prathap_1 — Wed, 27 Feb 2002 22:10:01 GMT

Hi Patrick
I have tried frecover -f /dev/rmt/1m -I > /tmp/some_file option, I am able to see the contents of the tape. Thanks for the info. How can I extract the tape contents into the disk.
Can you give me the syntax of the command to retrive onto disk.

Thanks
Prathap.

Re: Directory Checksum Error

Prathap_1 — Wed, 27 Feb 2002 22:12:49 GMT

Hi Shiju
Thanks for the info. I have tried the options given by you. But it is not showing the Backup type. It is giving the file type, whether it is ascii or English text or data file.

Thanks
Prathap.

Re: Directory Checksum Error

Prathap_1 — Wed, 27 Feb 2002 22:22:27 GMT

Hi Clay
I have tried the option given by you. Thanks for the info. But nothing is showing in the out put file. I am attaching the file called myfile. Can you go through once.

Thanks
Prathap.

Re: Directory Checksum Error

Helen French — Wed, 27 Feb 2002 22:29:08 GMT

Hi Prathap,

If you found it reading with frecover then for extracting use this:

# frecover -X -v -f /dev/rmt/1m

This will recover all files to the current working directory.

HTH,
Shiju

Re: Directory Checksum Error

A. Clay Stephenson — Thu, 28 Feb 2002 00:51:39 GMT

HI:

The od output indicates that this is an fbackup archive. The actual FBACKUP header begins at offset 1024 but you cut that portion off. In any event, this is an fbackup and an frestore will restore the files. Man fbackup/frestore for details.

Re: Directory Checksum Error

Prathap_1 — Thu, 28 Feb 2002 19:25:23 GMT

Hi Shiju
Thanks for the info. My problem is solved to some extent. The other problem I am facing is I am not able to read the contents of the tape either with tar, pax and frecover. I am getting the below errors with different methods.

1>tar : tape blocksize error.

2>frecover :
a.did not find expected file marker.
b.checksum on volume header is incorrect.
c.not an fbackup volume; magic value is incorrect.
d.did not find expected file marker.
e.Do you wish to try to salvage this volume? (^[yY]/^[nN]).

These are the error messages i am getting with frecover. Can you help me out in this issue.

Thanks
Prathap.

Re: Directory Checksum Error

Helen French — Thu, 28 Feb 2002 21:03:59 GMT

Hi Prathap,

You found out that the backup was taken by fbackup. So you don't need to try recovering it with tar. It will give you error. Try only frecover. See man frecover for more options and try ur luck !

Check this document, this describes your exact problem, may be helpful:

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=d2475f5911178f3548/screen=ckiDisplayDocument?docId=200000026600834

HTH,
Shiju

Re: Directory Checksum Error

Prathap_1 — Thu, 28 Feb 2002 22:40:27 GMT

Hi Shiju
Thnaks for the info. The link that you gave is for HP Version 10. I am working on B.11.00. How can I solve this problem on HP-UX B.11.00.

Thanks
Prathap.

Re: Directory Checksum Error

Helen French — Thu, 28 Feb 2002 23:44:44 GMT

Hi,

What type of tape drive are you using ? When was your data backed up ? Whis is the server ?

One possibility is a bad media. If your media is deffective, then you won't be able retrieve the data back. Check man pages of frecover and try using different options.

HTH,
Shiju