We have 3 9710's and have been working with STK a LOT to figure out how to
manage the cleaning. This is what we have been told/discovered so far:
In other STK libraries managed by ACSLS, the CLEAN function is handled
throught the ACSLS software. In the 9710 ONLY, STK moved the cleaning
function outboard; it is handled by the 9710 microcode, whether you are
using ACSLS or not. AUTOCLEAN is enabled by turning on the option using the
front panel of the 9710.
There is only 1 slot (a non-data slot) available for a cleaning cartridge of
each possible media type (3490 and DLT). There is a tiny cable that runs
from the drive to the robot. When the drive needs to be cleaned, it signals
the robot, and turns on the CLEANING REQUIRED light on the drive. The robot
will then mount the cleaning cartridge AFTER the current data tape is
dismounted.
I think I remember from previous posts that you have DLT drives in your
9710. The DLT drives have some peculiarities that complicate the cleaning
issue.
The 3490 technology drives request a cleaning after so many feet of tape
use. That makes it pretty simple to manage.
The DLT drives, on the other hand, can go for MONTHS without needing the
heads cleaned. The DLT drives dynamically monitor signal strength to the
heads. The drive requests a cleaning when it detects weakness in signal
strength. This can happen due to dirty heads, OR it can be tricked into
requesting a cleaning by weakness in the calibration tracks written on the
tape, OR by a slightly flaky tape. I believe that most of the cleans we see
are due to flaky tapes written by old levels of the microcode, not
legitimate cleans.
The result of this setup is that we got almost no benefit out of manually
cleaning the drives. If you want to manually clean them anyway, you
probably need to do it no more often than once a month, not weekly.
Another problem is that you can only clean after a dismount. That means
that if you are writing to a DLT tape and get I/O errors due to cleaning
problems, you will CONTINUE to get I/O errors and retries on that cartridge,
sometimes for hours, because the cleaning cannot occur until after the
dismount.
So in answer to your question, I have not figured any way to script a
cleaning of the DLT drives through ADSM. And I don't think you would get
much benefit from doing so.
If you are getting I/O errors, but the drive CLEANING REQUIRED light is NOT
on, then manual cleaning won't help - the I/O errors are due to something
else.
If you are getting I/O errors, and the CLEANING REQUIRED light is ON, and
the drives aren't cleaning themselves, you should call hardware support.
Either:
1) AUTOCLEAN is not properly enabled in the microcode
2) The cleaning cartridge is not in the correct slot
3) There is a problem with the cable connecting the drive to the robot for
clean signals.
Also, have the CE check the microcode level of your drives; make sure you
are up to at least V70.
Early releases of the DRIVE microcode had a faulty algorithm for writing the
calibration tracks which caused a LOT of unnecessary cleans when the tapes
were read back.
Hope this helps...
===============================================================
Wanda Prather
Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu
"Intelligence has much less practical application than you'd think."
- Scott Adams/Dilbert
===============================================================
> ----------
> From: Naveed Mustafa[SMTP:Naveed_Mustafa AT mckinsey DOT com]
> Sent: Monday, June 01, 1998 6:32 PM
> To: ADSM-L AT vm.marist DOT edu
> Subject: Auto Clean in Storage Tek 9710 libraries
>
> Naveed Mustafa@MCKINSEY
> 06/01/98 06:32 PM
>
>
> To: ADSM-L AT VM.MARIST DOT EDU
> cc:
> Subject: Auto Clean in Storage Tek 9710 libraries
>
>
> Hi All,
>
> We have enabled the AUTO CLEAN on the Storage Tek 9710 library, but are
> not
> seeing any advantage to that as the tape drives are not mounting the
> cleaning tapes automatically. This has resulted in the failure of some
> our
> tape drives also. Therefore, we now clean these tape drives every week
> manually.
>
> Does anyone have implemented a procedure to run it automatically either
> utilizing the AUTO CLEAN feature or by writing a script that would do the
> job.
>
> All suggestions are welcomed.
>
> Regards,
> Naveed.
>
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