Disbaling SCSI parity checking Compaq 1600

[Sureshbabu Nair]

Hi,

I am facing a problem with one of our Compaq 1600 Server running Linux (Redhat 9). I want to connect my Compaq 35/70GB DLT drive to this server, so that I can start some backup. But unfortunately, when connect the server with DLT and reboot my OS, during the OS loading i get a lot of Parity checking errors. I tried a lot of options using the Compaq Samrt Suite on the SCSI card, yet the SCSI parity error still comes on. I want to turn off the parity checking.

If anybody has any idea or has come across this situation before, please help me.

regards,
Sureshbabu Nair

[Uwe Zessin]

Parity is some kind of a checksum to verify data integrity. If you get parity errors (can you post the exact error text?) it usually means that the data got corrupted. I don't think it is a good idea to turn off the checks, because errors can go unnoticed then.

It could be a bad cable or a dirty connector.

[Stuart Browne]

Or it could be that the SCSI chain isn't terminated correctly.

But as Uwe suggested, lets start with the actual error messages.

[Sureshbabu Nair]

Hi Uwe and Stuart,

Thanks for the fast replies. Well the SCSI parity errors prevent my OS from booting. When redhat boots after initial detection all attahced devices, the SCSI parity checking is started and once that starts, the SCSI parity errors keep coming and the OS never boots up. Because of this I cannot even attach the exact errors. As far the termination is concerned the DLT supposed to be self terminating. But do you think is I should get a Terminator cable and test it.

thanks in advance,

Sureshbabu Nair

[Uwe Zessin]

I have never heard that the DLT tape drives do automatic termination, so I would try this before anything else.

[Stuart Browne]

Many drives (both DLT and DAT) are listed as self-terminating, but I've never trusted it. I've always had a terminator on the end of a SCSI chain, either Internal or External.

[Sureshbabu Nair]

Hi Stuart and Uwe,
Well I finnaly got hold of a terminator, though it was 68pin terminator and used 50pin to 68 connector to it to maken it work and connected to the DLT. Still I am getting the SCSI parity errors when i boot the system up. Still not sure what to do about it.. is there any way of by passing this scsi errors?

regards,

Suresh

[David Rosenberger]

I have the exact same problem with a Proliant 6000. I pulled the machine out of retirement to act as a backup server. Before it was replaced, it had NT 4.0 installed and Veritas backup had no problems with the tape whatsoever. I decided to go with RedHat 7.3 initially which gave me the parity errors, so I tried 6.2 which gave me the errors and now Fedora 1 which still gives me the errors. Are there issues with the sym53c8xx module and the Proliant?

[Sureshbabu Nair]

Hi,

I have finally given up setting up the Compaq 1600 as the backup box. I had to buy a brand new scsi card fit it into a generic desktop box with linux. Though the scsi errors still came in that box, but the box booted up fine and I then disabled the SCSI parity checking on the adpated card that got.
It works fine

regards,

Suresh