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DLT8000 problem

Gwen GUERIN_1
Occasional Visitor

DLT8000 problem

Please tell me why my HP DLT8000, C5725A, keeps on going back and forth, which results in very poor backup speed, something under 30MB/minute....I've tried with backup app integrated in WIN2003 server AND TapeWare, with the same problem......

thanks in advance!
8 REPLIES
Patrick Wallek
Honored Contributor

Re: DLT8000 problem

That is called "shoe-shining". The reason is that you are not feeding the tape drive enough data to keep the tape streaming. When the tape drive doesn't have data to write, it has to stop, rewind back to end of the data and then start writing again when it gets more data.

Really the only solution is to somehow figure out how to feed more data to the tape drive.
Devender Khatana
Honored Contributor

Re: DLT8000 problem

Hi,

Allthough you did not indicated anything of that sense but the frequency of such back & forth is more when drive experience more problems in reading/writing to media. This can be due to poor media or dirty/bad drive head. Try cleaning the head using cleaning cartridge & replaing the media.

HTH,
Devender
Impossible itself mentions "I m possible"
Gwen GUERIN_1
Occasional Visitor

Re: DLT8000 problem

should I try this DLT in another PC? with a good SCSI card i.e. a 29160...?

but I'm afraid that it's gonna be the same problem......

PS : the backup speed in the first seconds of backup is close to what it sould be, nut it only lasts a few seconds........
Richard Ward_6
Frequent Advisor

Re: DLT8000 problem

Do the servers involved have their network cards set to auto for Speed & Duplex? Sometimes they and the switch port they connect to need to be hardset to 100 Full Duplex or whatever. Check it out. I have had slow backups resulting from this before.
Gwen GUERIN_1
Occasional Visitor

Re: DLT8000 problem

what has network speed to do with my problem?? DLT drive is on the same machine than the files to be backed up......
Alexander M. Ermes
Honored Contributor

Re: DLT8000 problem

Hi there.
DId you daisychain your tape drive on the same interface as the disks ?
If yes, get a separate interface for the tape.
If you have a lot of small files, you may also have this problem, that you described.
That means, that the drive has to reposition the tape very often and has no datasrream continiously flowing.
Rgds
Alexander M. Ermes
.. and all these memories are going to vanish like tears in the rain! final words from Rutger Hauer in "Blade Runner"
gwen guerin
Occasional Contributor

Re: DLT8000 problem

and what if the drive had a problem....?? would it possible for it to work this way?

I've tried in 2 different machines, and it was the same result....

please help me, I've bought 20 DLT cartridges for it and I may never be able tu use them.....
Marino Meloni_1
Honored Contributor

Re: DLT8000 problem

you can use a tool to identify where the problem is comming from: LTT is the trick

-first collect a sticket and post it here, have a look and see if it give you some suggestions, then you can run several test in order to identify if your problem is comming from the server of from the drive, you have system test and device test, the first one, will check the speed of the data from the disk (source) to the server memory, the second test will check the speed of the data from the server memory to the tape (destination).

this will give you an idea on which part of the solution to work on

marino