Veritas-bu

[Veritas-bu] Re: DLT Cleaning

2000-04-07 09:53:26
Subject: [Veritas-bu] Re: DLT Cleaning
From: Roy Vosberg Roy.Vosberg AT veritas DOT com
Date: Fri, 7 Apr 2000 08:53:26 -0500
Some good reading on TapeAlert if anyone is interested:

http://www.quantum.com/src/configs/dlt_solution/dlt_sol_terms.htm

http://www.hp.com/tape/papers/tapealert.html


TapeAlert and NetBackup

To make the TapeAlert feature to work, there is nothing from the NBU
perspective that needs to be done, other than having a cleaning tape
enabled.  The drive, the robot, and the platform must all support that
feature.  If they all do, and a cleaning tape is defined, cleaning will
happen automatically.  

To find out whether the robot/drive/platform support the TapeAlert feature
or not, you must look in 2 places.

·       In the Release Notes, under the section "Supported Drives By
Platform", there are footnotes on the particular drives/platforms that
support TapeAlert.  

·       This needs to be used in conjunction with Appendix B of the Media
Manager SAG under the section called "Robot Attributes".  The attribute
called Drive Cleaning Support must say Yes.

Roy Vosberg


-----Original Message-----
From: acrocker AT lineone DOT net [mailto:acrocker AT lineone DOT net]
Sent: Friday, April 07, 2000 8:29 AM
To: Veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Re: DLT Cleaning


Some comments on this thread below...
>voila. when one of your DLT's needs cleaning, a TapeAlert signal will get
>sent, NetBackup will clean the drive, and after this happens frequently
>enough, your cron job will email you that your cleaning tape needs to be
>replaced. (note that this implies that you're running NBU 3.2 - I'm not

Only a few drive types support TapeAlert (most notably DLT7000 and STK9840).
I understood this was a new feature to 3.2. Earlier versions do not support
TapeAlert. 

Could some-one from Veritas explain what TapeAlert looks for as a signal to
initiate a clean? As Curtis says the drive privately informs the robot of
it's
need to clean so how have Veritas hooked into this - or are we simply
looking
for an 0x80 0x01 cleaning message in /var/adm/messages?

>The cleaning tape is abrasive and as such it will contribute to the
>wearing out of the expensive little heads of your expensive little
>DLT drives. :)

I'd just like to finally get to the bottom of this kind of statement. I
believe it to be popular myth!
I too also believed that excessive cleaning of DLT drives would increase
headwear however I've recently
been told categorically by an STK trainer that a DLT cleaning tape is simply
a standard tape that has not
gone through the burnishing process. As such it's a standard tape (same
thickness, same material)
as a data tape only not polished. Since it's movement over the heads is
identical to a data tape it is
impossible to consider that it will increase headwear. I'm not saying this
is the truth, but it's the
version of the truth which I currently believe :o)

Frankly the only thing overcleaning will hurt is your pocket - these tapes
ain't cheap!

Does anyone have an evidence to contribute?

Alan                    

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