Date: Tue, 21 Jun 2005 15:30:08 +0200 From: Pavel Duda <element@email.cz> To: freebsd-questions@freebsd.org Subject: Re: DDS Tape problems Message-ID: <d994do$9tf$1@sea.gmane.org> In-Reply-To: <200506201355.j5KDtLjP006948@clunix.cl.msu.edu> References: <d968h5$21k$1@sea.gmane.org> <200506201355.j5KDtLjP006948@clunix.cl.msu.edu>
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Jerry McAllister wrote: >>Alex Zbyslaw wrote: >> >>>Pavel Duda wrote: >>> >>> >>>>Hi, >>>>I have problem with my DDS-3 type drive. I'm able to write on it but >>>>not read data back. If I try to read them I get card dump and tape >>>>drive hangs up. I have tried to upgrade firmware but problem remains. >>>>Does somebody have experience with this ? > > > We have had a lot of experience with seeing similar problems, but little > with solving it. We have about 75 systems with mostly DDS-3 some are > DDS-4. All Are SCSI. All were on Dell Poweredge machines and are which > ever vendor OEM model they were installing at the moment - but we couldn't > seem to identify a clear difference from one model to the next. > > More than half seem to have been working fine for several years. > The rest have continual problems with symptoms similar to yours - > it appears to write OK, but the tape is unreadable. There appears to > be stuff on the tape but it is junk. I say this because skips and > rewinds take about the amount of time I would expect, but of course > that is not a definitive test. Also, sometimes I can cat or dd a file > off the tape that is junk (eg the file is junk - not readable as anything. > But often I cannot get anything at all. Some got errors during the write. > > I think there are multiple problems with the DDS drives, some of which > may be their own hardware on internal control and some may be the > SCSI controller or the drivers, but I have never been able to pin > anything down and after asking several questions on the lists over > several years, have had no response other than some people agreeing > and some stabs with additional questions to answer that all went nowhere. > > In a couple of cases, getting the drive replaced seemed to fix the > problem. I believe the ones that warranty replacement helped were the > ones that failed during write. In others I don't think rplacement helped. > Some sites have upgraded to DLT. > > I know none of this helps much toward solving the problem, but I post > this response for moral support and in hopes of jogging someone who > might know more about these things. > > ////jerry > > > >>>>My specs : >>>>FreeBSD 5.2.1, generic kernel, x86 (P3), SCSI card is Adaptec AHA2940 >>>>and tape drive Python 04106. >>> >>>Not terribly helpful, but I have a DAT2 working with an Adaptec 2940A. >>>It's worked since forever and is fine with 5.4 though I never ran >>>5.1/2/3. Is the machine it's attached to dual-boot? I.e. can you test >>>the tape drive in Windows, or Linux for example? (Well, they have to be >>>good for something :-)) Is this a recent problem or is this the first >>>time you've tried using this drive? Can you try another SCSI adapter? >>>I've run mine (for testing only) off the cheapest rubbish I got free >>>with a SCSI CDRW and it was fine. >> >>I was trying to use Tekram SCSI adapter with same result. I have taken >>this DDS tape from my AIX machine (netfinity) where it was working wo >>problems. >> >> >>>The only other guess would be termination. Has anything else on your >>>SCSI chain changed? Is the terminator properly plugged in? >> >>Termination should be fine. I have tried both variants - termination on >>tape and termination via active terminator on cable. >> >> >>>--Alex >>> > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" > I've just switched tape drive for a DDS-4 and this one works fine. Funny is that DDS3 drive works wo problems on my workstation with Windows and same (well same type not exactly same) SCSI adapter. I have also found some information that there could be problem with SCSI commands queueing, but no solution for that or what it causes. Anyway now I'm happy that DDS-4 in server works fine so I probably wont dig deeper to find out where is the problem.... Pavel
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