a708@mindlink.UUCP (Gord Wait) (11/01/90)
We have had an Exabyte drive on our Sun Sparc Network for 6 months or so, and so far I have NEVER had a tape error listed... In fact it makes me feel paranoid that there are no errors at all.. but several tests of the tapes I make show they are fine. My only beef is the fan, which should be: 1. Slower or 2. Blowing the other way, cause the tape drive sucks up dust like a vacuum cleaner, so there is almost always a ring of dust around the tape door.... Gord Wait
bobw@cd_player.wv.tek.com (Bob Wood) (11/06/90)
In article <16227@hydra.gatech.EDU>, ken@dali.gatech.edu (Ken Seefried iii) writes: > Path: orca.wv.tek.com!zephyr.ens.tek.com!uunet!know!zaphod.mps.ohio-state.edu! ncar!gatech!prism!dali.gatech.edu!ken > From: ken@dali.gatech.edu (Ken Seefried iii) > Newsgroups: comp.unix.admin,comp.periphs.scsi > Subject: Exabyte woes... > Message-ID: <16227@hydra.gatech.EDU> > Date: 1 Nov 90 19:04:52 GMT > Sender: news@prism.gatech.EDU > Reply-To: ken@dali.gatech.edu (Ken Seefried iii) > Followup-To: comp.unix.admin > Distribution: usa > Organization: The House Of Fun > Lines: 27 > Xref: orca.wv.tek.com comp.unix.admin:446 comp.periphs.scsi:1281 > > --- > > My company has an Exabyte attached to a Tektronix XD88/10 > that we use to backup a large number of machines over NFS. > The problem is that when I restore files from these tapes, > I'm always having to use the cpio -k option (skip bad > headers) due to the large number of "out of sync" errors > that I get (some tapes have 60-100/1.8GB). We generally > use Fuji or Sony tapes, and the tapes are pretty new (each > used around 4 times). > > My questions are: Is this normal? NO! > Is it a simple matter > that the drive needs to be cleaned/aligned/etc.?> Possibly. Exabyte recommends cleaning the drive after every thirty hours of operation if my memory serves me right. In our test we have been able to run for longer periods of time with no problems. However we have seen cases where cleaning solved drive problems with the Exabyte. This is different than the 1/4 inch cartridge drives. I don't know if I have ever seen any one clean one of them. > Are different tapes the answer? Probably not, at least not with the Sony tapes. Exabyte brand tapes are selected for low drop out rate. With the Sony tapes you may get a few more >>recovered<< errors. Cpio should never see these, you may lose a few kilobyts of capacity. Our engineering stockroom sometimes stocks Sony tapes for internal use. > Is there another solution? Maybe. If your Exabyte is from Tektronix you should report the problem to your field office. We still have resources to address such problems. If you bought your Exabyte drive from someone else there is one thing you can try. When we(Tek) ship Exabytes we set a couple of the internal dip switches differently than the Exabyte default. Specifically we turn on(up) switches 1 and 3 on the dip on the 2nd board from the back, the MX board. This is not the SCSI address dip, that is on the 1st board. Switch one controls the length of the memory test. Turning it on will greatly shorten the self test time when the drive is powered up or reset(this is not your problem though). Switch 3 when on forces the Exabyt to only disconnect on even byte boundries. Our driver was designed so this would not make any difference. Unfortunately there is a bug in the driver which only shows up when a SCSI transfer starts at an odd byte boundry. The Exabyte seems to be the only device which does this as part of a disconnect/reconnect sequence. You can work around the bug by turning on switch 3. The problem is fixed in release 3.2.e.1. The problem happens when writing a tape not reading. If you want additional evidence before tearing into your Exabyte drive you can try repeatedly reading a tape and see if the cpio errors are always in the same place. Then rewrite the tape and try reading it a few more times and see if the errors are now repeatable but in different places. If so there is a good chance turning switch 3 on, or waiting for 3.2.e.1, will fix your problem. The bug can also cause the system to crash with a panic "sleep at interrupt depth 1" message, or something very close to that. > > On a similar note, does anyone know of a backup package, > commercial or PD, that works with Exabyte, NFS (even, > within reason, older NFS implimentations that don't allow > -r=0), and *very* heterogenous networks (we have one of > everything). > > Thanks... > > -- > ken seefried iii "A sneer, a snarl, a whip that > ken@dali.gatech.edu stings...these are a few of > my favorite things..."
rob@hpcpbla.HP.COM (Rob Morling) (11/16/90)
Re: Exabyte woes. Ever thought about a DAT backup solution? Rob Morling