Messages in this thread | | | Date | Thu, 28 Mar 1996 13:18:07 -0600 (CST) | From | Doug Ledford <> | Subject | Re: SCSI bug |
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First off, sorry to redirect this to the list, but the original author had sirdir@localhost.rutgers.edu, which of course maps out to 127.0.0.1 and won't work for mailing to him directly.
On Thu, 28 Mar 1996, Egbert Eich wrote:
> Andrew C. Esh writes: > > sirdir wrote: > > > > > > Hi > > > I encoutered a 'bug' in the SCSI subsystem of Linux. I have a harddrive > > > that spins down now and then to do some sort of recalibration (silly > > > thing, I know... but otherwise it's fast and big) .. And yes, if I say it > > ... > > This discussion is on the wrong list. You should direct it to the SCSI list. > > > > > > > anyways, i hope somebody can fix this problem... i love linux, but with > > > this harddrive it's somewhat unusable... > > > > The drive is unreliable anyway. It's not the fault of the OS. If you > > get it repaired, let me know what they did to it. I need to have mine > > fixed too. (Is it possible you have the drive in power-saver mode?) > >
In the past I have found two reasons other than drive manufacture that can cause drives to spin down. You may want to check these out. The first is the power supply. I had an SCO Unix box with a 2GB HP SCSI drive in it. The drive would occasionally spin down for no good reason. After putting a digital multimeter on the 12V line out of the power supply and having it monitor with min and max saves on, I found that the 12V line would occasionally drop to as low as 10.5V. At 10.5V, the HP drive would spin down but the controller board would still work. However, since the controller didn't tell the spindle motor to spin down, it was confused and would return a LONG string of drive read/write errors and the machine would crash.
The second cause for this type of activity was one of the power connectors for a cpu fan was plugged in between the power supply and the drive. The connector (as many are) was unreliable any time you wiggled the wires. The end result was, I took this connector and moved it elsewhere and the drive quit spinning down.
> > The drive is not broken. Some of the low-priced IBM-drives do this, > they have to go into a maintenace mode every 72 hours to recalibrate, therfore > they spin down completely for 1-2 minutes (I don't recall exactly).
However, if the drive in question isn't a low priced IBM, then it could very well be broken, or it could be one of the two scenarios I mentioned above.
> > > > BTW: SCSI drives are *not* supposed to spin down by themselves without > > being instructed to do so by the OS. This would be catastrophic.
They can spin down on there own, but it must be instructed to do so by the controller on the drive or else it would also be confused and not know what to do with requests, see above.
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