On Sat, 25 Oct 2008, Curtis Preston wrote:

That would be every couple of days in a few shops.  Where did you read that?  
My understanding was what the previous folks said, that it was an on-demand 
thing.



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-----Original Message-----
From: veritas-bu-bounces AT mailman.eng.auburn DOT edu 
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of smpt
Sent: Saturday, October 25, 2008 9:12 AM
To: 'Justin Piszcz'; 'A Darren Dunham'
Cc: Veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Poll: How many times do you use a cleaning tape?

IBM LTO3 and LTO4 requires cleaning every 16 TB of data.
stefanos

-----Original Message-----
From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Justin
Piszcz
Sent: Tuesday, October 14, 2008 1:10 AM
To: A Darren Dunham
Cc: Veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Poll: How many times do you use a cleaning tape?



On Mon, 13 Oct 2008, A Darren Dunham wrote:

On Mon, Oct 13, 2008 at 04:54:22PM -0400, Justin Piszcz wrote:

Also I've read / heard its best to let LTO-3 LTO-4 drives set the tape
alert flag when they need cleaning vs. cleaning drives at intervals
(which is recommended for sure with LTO-2) -- what have you observed?

I'm not sure which you're saying is recommended for LTO-2.  As far as
I'm aware, periodic cleaning is not recommended for any model of LTO
drive.  This is documented for HP and IBM drives:

HP
   Should I do regular cleaning like DDS?

   The HP Ultrium drive is designed to require very minimal
   cleaning. The internal head cleaner provides an effective
   preventative cleaning against head contamination. Regular cleaning
   using cleaning cartridge is not necessary. Do not use a cleaning
   cartridge unless the drive requests it and the Use Cleaning
   Cartridge

IBM
   The IBM Ultrium LTO Tape Drive was intentionally designed to be
   self-monitoring and self-cleaning. Therefore, the IBM recommendation
   is not to manually clean the tape drive, but rather to use the
   automatic cleaning function provided with the library or by your
   application.

   Each drive determines when it needs to be cleaned and alerts the
   library or your application.

   In order to prevent recontamination of drive surfaces, you are
   limited to using a specific cleaner cartridge a maximum of 50 times.

   Note: Do not manually initiate drive cleaning unless requested by
   support engineers. LTO drives are self-cleaning and will require
   infrequent cleaning using cleaning cartridges.

I found the document I was thinking of.  HP LTO-1 uses 18.5 meters of
cleaning tape, other models use 5.5 meters.  So you get 15 on an LTO1
and 50+ on LTO-2 and LTO-3 (and I assume on LTO-4 as well).

I love whoever proofread this sentence.  (...up to at least..)

  IMPORTANT: A cleaning cartridge can be used up to at least 50 times
  (LTO2 and LTO3) or 15 times (LTO1). The cleaning cartridge is ejected
  immediately if it has expired or if it is not an approved Ultrium
  cleaning cartridge. Discard it and use a new one.

Technically, because the cleaning usage algorithm isn't mandated,
there's no way for a universal cleaning *tape* manufacturer to know what
the usage will be beforehand.  A manufacturer could use more or less.
However, it appears that both IBM and HP use 50 on recent drives.

--
Darren

Very nice information/description, thanks!

Justin.
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