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Tape Errors - Openserver 5.0.7

© June 2005 JIW

Author: JIW

Having trouble with an IDE tape drive - Dell Powervault 100T (Travan 20/40 Gb drive). Server is a Dell Poweredge 800, P4 2.8Ghz, 1Gb Ram, SCSI HDD's. SCO Openserver 5.0.7 with MP3 installed. I have installed the tape drive using mkdev tape, and it seems to have been added successfully, however whenever we try to use it we get errors like:

dd if=/dev/rct0 of=/tmp/nigel.tape count=100 
dd: read error: I/O error (error 5) 
cpio -itv</dev/rct0 
cpio: I/O error on read(). 

Syslog says:

Jun 24 10:42:50 scosysv WARNING: wdRdWrData(unit
0) read overrun: requested 6, g
ot 14 words 
Jun 24 10:42:50 scosysv NOTICE: Stp: Error on
SCSI tape 0 (ha=0 bus=0 id=0 lun=0
Jun 24 10:42:50 scosysv         Illegal request 

Any help would be very much appreciated. I hope I have provided enough info.

Jason Wood - jason@gane.co.uk

List of other SCSI error codes

Be sure to see the comments for information on SCO's "wd" driver.

Got something to add? Send me email.

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Fri Jun 24 12:51:44 2005: 697   dhart

What is it you're expecting to find on the tape? If it contains something other than a dd image or cpio backup you might well get such goofy errors.

I wonder if what you have is really a tar backup. But first make sure the drive works:

Have you tried writing to a blank tape and reading it back?

cd /tmp
tar cvbf 20 /dev/rct0 .

Please note the trailing dot. This will backup your tmp directory and won't take long. Read it back like this.

tar tvf /dev/rct0

This simply lists what is on tape with out writing to disk.

If that doesn't work either, then the trouble is in the way you configured the drive into the system or with the tape drive.

Unfortunately I find myself uniformly disappointed with tra van drives.

Fri Jun 24 13:09:05 2005: 698   TonyLawrence

No, this is a driver problem. There is a wd driver at ftp://ftp.sco.com/pub/openserver5/drivers/OSR507/btld/wd/ but I don't know if that would help. The readme doesn't mention tape, and it's unclear whether you alread have this with MP3.

If Bela Lubkin happens to see this he might know better.

Fri Jun 24 14:38:35 2005: 700   BigDumbDInosaur

IDE tape drives of any kind are a poor backup solution. However, the Travan format takes the grand prize for crappiness in all respects. Better to invest in a DDS tape drive, or if backups aren't expected to go much over 4 gigs, DVD-RAM. Stay away from that IDE stuff if at all possible. IDE support in SCO is rather lame.

Fri Jun 24 16:05:36 2005: 705   rbailin

Tony, the current version of the wd driver for 5.0.7 is found here:


It requires that MP3 be installed first, so one can assume that it
is more current than the wd driver included with MP3.

And I second the notion that Travan drives suck. DDS4 or 5, or
AIT drives (preferably) are the way to go for inexpensive,
large capacity solutions. With a SCSI interface, of course.


Fri Jun 24 17:17:41 2005: 706   TonyLawrence

I have more than once considered modifying the on-site search here so that when it sees "Travan" its first response would be "JUNK - JUNK - DON'T USE - JUNK".

Sun Jun 26 22:03:38 2005: 720   bruceg2004

I'll second that! Travan drives are JUNK. I had to diagnose a problem on an aging server, which had a travan drive, and recommended they install a Iomega REV drive, due to the size required of the backup, and it turned out to be a much better backup drive.

Mon Jun 27 04:56:41 2005: 721   BigDumbDinosaur

Funny how this goes: this evening, a client called me to moan and groan about the Travan drive in his PC, which we built for him about 6 years ago and upgrade late last year. At the time, he asked for tape backup and I suggested to him a DDS2 drive, since the amount of data to be backed up was within that range. He balked at the price of the drive and requisite host adapter. I explained to him that the only option other than DDS format would be a Travan drive, which we did not recommend because of ongoing reliability issues, as well as absurd cartridge costs. He insisted on the Travan drive, so we fixed him up with an H-P model.

The drive has been replaced twice since the machine was built, both times under warranty by H-P. The third failure, which occurred late last year, could not be handled via warranty, and again, against my advice, this client insisted on us furnishing him with another Travan drive. The only thing that our distributor could provide was a Seagate product, as H-P had (wisely, in my opinion) discontinued selling Travan drives. So Seagate it was (along with that atrocious backup software they supply). Tonight (June 26th), my client called saying he can no longer generate a viable backup.

My advice to him, once again, was to go with DDS. None of the available optical solutions would work for him, as the capacity wasn't adequate. He's still unwilling to get a DDS tape drive, again citing cost as the reason. I tried to get him to see that he had already spent that amount of money on two tape drives that don't work, along with the added cost of the cartridges. No dice. I ended the conversation by telling him I would not support his system any more, as he had made a choice that was incompatible with good service. Also, he had, in effect, stated that his data wasn't sufficiently valuable to warrant a reliable backup solution.

This is one of the few instances where I have told a client I can't help him. In this particular case, I simply can't see killing myself to support a product with an indefensible record of failure. I'm really hoping this guy will come to his senses and make the right choice. Otherwise, he'll just be one more victim of Travan trash.

Mon Jun 27 07:34:56 2005: 722   Bela

It is worthwhile to try the latest OSR507 "wd" driver, but there's only a small chance that it will help. There weren't really any ATAPI-related fixes during the 507 timeframe. To be clear: I'm saying that there _is_ a chance it would help, just not a _big_ chance. It's worth trying.

ATAPI tape (and CD/DVD) drives are hampered on OSR5 by the fact that the "wd" IDE driver only uses UltraDMA with hard disks. ATAPI devices are limited to PIO modes, which are much slower and more CPU-intensive. I understand that this is corrected in OSR6. (OSR6 drivers are not at all portable to OSR5. There was always talk of implementing UDMA for ATAPI on OSR5, but it never happened and I doubt it will happen now that OSR6 is out.)

I would agree with the characterization of Travan as "junk", but I am aware that my opinion is strongly colored by my OSR5 background -- an OS which has not only the no-UDMA issue but also hasn't had any real work done on the ATAPI subsystem in 6+ years. I've had discussions with Tom Podnar of MicroLite (BackupEdge) in which he seemed to believe that Travan on Linux, Windows and other OSes was not so bad at all. Or maybe I'm misremembering, maybe he was saying that _non-ATAPI_ (i.e. SCSI, USB or FireWire, whichever may exist) Travan drives were OK.


Mon Jun 27 11:16:09 2005: 724   JIW

Thanks for your replies - This machine is a replacement server for use internally, so I'm going to try and salvage a SCSI tape drive from somewhere - not sure why an IDE drive was specified in the first place, as the server is SCSI 'ready' anyway. I read the help text on the wd driver on the SCO site, but the impression I get is that if you have installed MP3 then you have the latest driver. Just out of interest - is it possible to disable DMA on IDE devices IE force them into PIO mode?

Thanks again,

Mon Jun 27 11:39:36 2005: 725   Bela

> I read the help text on the wd driver on the SCO site, but the impression
> I get is that if you have installed MP3 then you have the latest driver.

MP3 was co-developed with a bunch of other stuff, including that driver update. All of those co-developed pieces were then shipped on a single CD which was also sometimes referred to as "MP3". If you have installed everything on the MP3 update CD then yes, you have the updated "wd" driver. If you only installed the MP3 component, I'm not so sure. (It may still have been included in the MP3 component. I forget at this point. In either case, attempting to install the separate "wd" component won't cause harm.)


Mon Jun 27 11:50:12 2005: 726   TonyLawrence

I've had problems with SCSI Travan drives too, though I'd have to say less so than the IDE, which as Bela notes is probably from OSR5's bad IDE drivers. In fairness to the OS, that probably at least partially came from a "why on earth would you ever use IDE devices on a real server" attitude.

I have not used Travan on Linux - most of my Linux sites are small enough to use DVD-RAM and the ones that aren't can usually use IOMEGA REV, and the few that need bigger or faster certainly aren't going to consider Travan.

Mon Jun 27 18:44:36 2005: 727   Bela

> In fairness to the OS, that probably at least partially came from a "why
> on earth would you ever use IDE devices on a real server" attitude.

Yes, largely that -- but countered by a _very large_ number of requests from users to make it work better. That is, despite it being a bad idea and reinforced by poor support from the OS, many customers did it anyway. Money talks, eh? The support should have been improved.



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