Re: Tape Drive Needs to Be Cleaned

A few years ago, I read an article about drives and errors in a pc. It was
enlightening. The controller in a pc is smart enough to do multiple
retries all by itself. And, after a certain number of retries, the drive
is instructed to do an aggressive read. Just means that amplification is
ramped up. Sad thing about that is that DOS and Windows ignored the detail
from the controller that it did have issues, which it solved by itself.
Thus, we would eventually get the infamous Abort, Retry, Fail message.

I can't help but wonder if the i might be doing something similar.
PRTERRLOG shows temporary read and write errors. But, are those soft
errors only getting reported when the drive itself has finally given up and
then the operating system is involved?

Also, I am wondering how good a tape cleaning cartridge is. It can clean
heads and anyplace the tape touches. But, what about other debris inside
the drive? Could drive be dirty and debris be moving around inside? Is
drive cleaning with a swab possible? Is that an IBM only thing? Our 3590
got cantankerous, so IBM was called. Despite regular running of the
cleaning tape, it had issues. In this case, for whatever reason, all that
seemed was done was drive itself was powered down for a minute. On power
up, it ran full diagnostics. May have done other things like some manner
of recalibration. No errors were reported and drive works fine again. I
can't recall if IBM did any cleaning on it.

John McKee


On Thu, Nov 7, 2013 at 7:34 AM, Jim Oberholtzer<midrangel@xxxxxxxxxxxxxxxxx

> wrote:
> Get new tapes!!!! They are leaving bits and pieces of themselves
> behind. The report only records when a tape unit actually reported a
> fault in read or write, not if it's disintegrating.
>
> The other option is the tape device itself is getting so the read/write
> heads are out of alignment. Only solution there is to swap the tape
> unit out. Being a model 250 I'm guessing it's not under maintenance.
> You need to call Larry/Pete to virtualize that box and be done with it.
>
> Jim Oberholtzer
> Chief Technical Architect
> Agile Technology Architects
>
>
> On 11/7/2013 7:20 AM, Jerry C. Adams wrote:

> > My former employer, now client, has a Model 250 with an internal tape

> drive

> > (6382 Model 001). Typically it needs to be cleaned every one to two

> months.

> > Lately the system started issuing the message (CPF6792) every week. This
> > week it has issued the message every day, despite the fact that,

> according

> > to the bookkeeper, the cleaning cartridge has been inserted and run every
> > morning.
> >
> >
> >
> > The nightly backup seems to be running successfully, and I run the

> PRTERRLOG

> > (Volume Statistics) every weekend, which has not indicated that any tape
> > needs to be replaced.
> >
> >
> >
> > So, any idea, clue, or suggestion why the system (V5R1, if important)

> tells

> > us that the drive needs to be cleaned?
> >
> >
> >
> > Another thing, which I have always wondered: How does the system know

> that

> > the drive needs to be cleaned? The answer may offer a clue to the

> original

> > problem.
> >
> >
> >
> > Thanks.
> >
> >
> >
> > Jerry C. Adams
> >
> > IBM i Programmer/Analyst
> >
> > I always figured the American public wanted a solemn ass for President,

> so I

> > went along with them. -Calvin Coolidge
> >
> > --