Tar - directory checksum error

[David Preston_4]

I have 2 K2xx systems, I have made a tar tape (DAT2) on one box, and am trying to load it to the other, but every time I try to copy or even view the tape I get a directory checksum error and it aborts, but never at the same place. but the tape is fine on the machine I made it on.

any suggestions???

Dave

[Ravi_8]

Hi,
is the system on which you wanted to extract does has sufficient space?

[David Preston_4]

Yep, volume sizes are almost identicle

d

[Michael Duthie]

Are both drives the same type of DDS, 1,2 or 3?

check with ioscan -fnkCtape.

[Joseph C. Denman]

I have had problems like this in the past. It is probably either the tape or one of the drives.

First, try a new tape. There could be a problem with the tape that only one of the machines is catching.

If you experience problems with a new tape, the problem is probably the head alignment on one of the drives is off slightly. You will need to identify which drive is causing the problem then have it replaced.

...jcd...

[MANOJ SRIVASTAVA]

Hi David

Incase both the drives are DDS-3 ( you can check by giving mt -f /dev/rmt/0m status ) .Then the problem lies with compatibility in terms of head alingment , though each drive will read and write the tape properly but a tape written on one will not be read by other . It is similar to the VCR tape which work fine on one VCR but not on the other . SO the solution is that replace one of the drives and the tapes can be read across. This happens very rarely but has happened to our computers once in the recent past.


Manoj Srivastava

[Carl Erhorn]

Hi.

Be careful to check that you are using the same version of tar on both machines. If the tape was made with GNU tar, you may have problems reading the tape back with the native tar.

The GNU tar has it's own particular way of handling deeply nested paths, and it is not the same as most native tar programs.

In that case, you can sometimes get past the error by using a tar command line switch to ignore checksum errors, but not all tar versions support this option.

A better solution is to obtain the same tar used to create the tape, and use that. It should always be able to read the tapes it created.

If you are not getting I/O or read errors, it usually means there is a software problem, not a problem reading the tape. Try using the 'dd' program to read the tape. If it reads all the way to the end with no errors, then you are not having a problem reading the tape, and you should focus on differences in the software on the two machines.

If you get different error messages from 'dd', that should point you in the right direction to solve the problem.

Best of luck,
--Carl

[Carlos Fernandez Riera]

If both driver are DDS2:

1- use cleaning tape in both drivers. once or twice. And try a new tape.

2- check with dd for I/O errors.
dd if=/dev/.... of=/dev/null bs=10k

3- dd if=/dev/.... of=/tmp/dd.1 bs=10k count=1
file /tmp/dd.1
tar tvf /tmp/dd.1

4- dd if=/dev/... bs=10k | tar tvf -

[David Preston_4]

Thank you all for your suggestions, I found out that there is a high probability that there is a hardware issue as the server had a similar issue previously. so I will follow up with that.

thanks again, this forum helps me alot.

Dave