I/O Error

[Saeid Ghanei_1]

I try to do an ignite backup on tape, but then after I can not read the tape, I/O error. I cleaned the tape drives many times. It seems to be an I/O problem on tape. I tried another tape drive, the same problem. I changed the terminator also but not helped.
If I write to tape and read from tape, the cheksum is different.
The tape drive is in an enclosure with a CDROM. CDROM is working fine.
What could be the problem?
Thanx
Saeid

[Sudeesh]

Reading igite tape is not straight forward, can you post the commands you used?

Why dont you just tar some files to the tape and try reading them? This will help you to pin point were the issue is.

Sudeesh

[Saeid Ghanei_1]

I found the error during ignite backup. I tried many times to write to tape, every time is doing but the checksum is wrong. I tried stm, verify is doing the loop many times and stop by warning (loop was faulty). With exercise, I get the following error:
-- Exercise Failure Log for SCSI Tape on path 0/0/1/0.3.0 --

Started: Wed Sep 21 00:17:50 2005
Failed: Wed Sep 21 00:17:50 2005

Number of seconds allocated: 600
Number of seconds completed: 377

The actual record written to device special file (!) is larger than the one
specified by write system call.

Possible Cause/Recommended Action (in order of probability):

There is a hardware problem on the selected device.
Replace or repair the device.

The scratch media in the selected device drive is faulty.
Replace media and restart the exerciser.

The head of the device is dirty.
Clean the head and restart the exerciser.

Internal Application Error.

Here is the verify log:
-- Verify Activity Log for SCSI Tape on path 0/0/1/0.3.0 --

Log creation time:
Wed Sep 21 03:18:01 2005

Wed Sep 21 03:18:01 2005: Verify tool (tape) starting on path (0/0/1/0.3.0)
with the following tool options:

Wed Sep 21 03:18:01 2005: The tool will loop 1 time(s).

Wed Sep 21 03:18:01 2005: The tool will continue execution until a maximum
of 10 error(s) occur(s).

Wed Sep 21 03:18:01 2005: The tool will perform medium test coverage. This
means the tool will perform its testing as quickly
as possible but will achieve as much test coverage
as possible without taking an excessive amount of
time.

Wed Sep 21 03:18:37 2005: File Compare Error on File (1).
Byte written: (A), byte read: (Ã ).

Wed Sep 21 03:18:37 2005: Read data does not match written data.

Possible Cause/Recommended Action (in order of
probability):

There is a hardware problem on the device.
Replace or repair the device.

The scratch media in the drive is faulty.
Replace media and restart the verifier.

The head of the device is dirty.
Clean the head and restart the verifier.

Wed Sep 21 03:18:37 2005: Of the 1 loop(s) performed by the READ/WRITE test, -1
loop(s) was/were successful and 2 loops(s) resulted
in a warning.

Wed Sep 21 03:18:37 2005: Tool completed with exit_status MOD_WARNING (1)
indicating tool completed with a warning.

[Sudeesh]

Try cleaning and then check the drive with a fresh tape. If this fails it is time to log a hardware call and get your drive replaced.


Sudeesh

[Saeid Ghanei_1]

I cleaned the tape many times and tried many tapes without success. I changed the tape drive but with the other tape drive I have the same error! May be the enclosure is defect!

[Fred Martin_1]

Try using something other that ignite, to help you determine if the drive or tape is at fault.

Try writing files to a tape like this:

# find /var/tmp -type f | cpio -ocuvB > /dev/YOUR-TAPE-DEVICE

Use your own tape device, whatever that may be.

Do you still get I/O error?

If not, then the problem is with ignite.

If you do, the problem may be the tape or drive.

[Tim D Fulford]

I think the diagnostics may have it all. If you've cleaned the tape device, changed the tape.. then all you are left with is a H/W fault... Call HP/supplier and chit it fixed.

Tim

[Bill Hassell]

The output of STM is fairly conclusive and matches what you are seeing with Ignite. Replace the tape drive. If the error still persists, try disconnecting all other devices on the SCSI bus including the CDROM (but still keep the terminator in place). If it still fails, there may be a problem with the SCSI I/O card. Do you have another SCSI bus to try?

[Saeid Ghanei_1]

Thanks, but I have still replaced the tape drive and terminator also but no success. I opened a call by HP HW. Let´s see what´s happened!

[Sean Dale]

Does the ioscan command show the hardware as claimed? Also, make sure there aren't any hardware paths to the device that are not in use.