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Wanting to have tapes that are not full be written to until they are full, and 'full/appendable" designation

  • 31 March 2022
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Userlevel 2
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I have 2 hopefully related questions to tape writing/usage. please pardon my ignorance :)

  1. I am seeing tapes that are “never being written to again” and are not full at all with this message “Marked full/appendable due to media group switching to a different data path”. My assumption is that the tape was writing, and then something happened to the job… but shouldn’t it not be “marked” as anything, and just be ‘appendable” until its full?  We have ( in the tape library properties) “mark media appendable” and “use appendable media” set to 90 days”. These tapes are not > 90 days old.  is there a way to unmark them or not cause them to be marked “full/appendable” (whatever that means? why full and also appendable?)
  1.  In the docs for “Default Scratch” media group, I see these settings (below).  I want to have any tape that’s “not full yet”  to be picked before any other “completely empty” tapes.  What setting should I choose? The ‘reused” and “recycled” terms below don’t make sense to me. Currently we have this set to “Use least reused media first” which I think is using “less full” tapes before “fuller” ones?  or it it choosing ‘empty” tapes ( the least reused?) before trying to fill up a tape has been written to?

Spare/Cleaning Media Selection Criteria

  • Use most reused media first

    Specifies that the most recycled media is used first when a job requires a media, and that there is recycled media available in the scratch pool.

  • Use least reused media first

    Specifies that the least recycled media or new media is used first when a job requires a media, and that there is new media is available in the scratch pool.

  • Use media based on capacity

    Specifies whether you want to use and fill the lower capacity media first or the higher capacity media first.

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Best answer by Matt Medvedeff 31 March 2022, 19:45

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2 replies

Userlevel 4
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Hello @tigger2 

For question 1:

See the docs here as to why a Tape can get flagged as Appendable (scroll to the bottom of the page) - https://documentation.commvault.com/11.24/expert/10261_media_properties.html

For more info on Appendable media see the docs here as well - https://documentation.commvault.com/11.24/expert/9949_library_properties_overview.html#mark-media-appendable

Based on the message you are seeing it sounds like it was marked Appendable because an Alternative Data path was used. A common occurrence that can cause this is if the tape was being actively written to and something (drive/communication issue usually) caused the job to failover to a different tape in another drive.

There’s no way to unflag these tapes when this condition occurs, the data will need to age off and then these tapes can be reused.

 

Question 2:

For context reused/recycled applies to a tape that was previously used by Commvault and all of the jobs on it have aged. So the media is recycled and becomes a reusable scratch tape.

By Default the system will write to a partially full tape from the Assigned media pool as opposed to a blank tape from the Scratch pool (Unless you specify to use new media when the job is launched). So partially full media always has priority over new/recycled media. This option only applies to how you want CV to utilize the new/recycled tapes in the Scratch Pool when new media is required for a job.

How you want to handle this is up to your decision. The default option is Use least reused media first. Meaning it’ll prioritize tapes that have been used less and have likely have less physical wear and tear.

Hope this answers your questions. Thanks!

 

 

 

 

 

Userlevel 2
Badge +11

Thanks! 

I think part of my issue/confusion is that we don’t reuse tapes where I’m at (all are “infinite” retention, and none get reused, which is likely an uncommon scenario) so I’m unfamiliar with doing this in CommVault, and our system isn’t set up to do this (settings, processes and procedures, etc.)

 

It makes *some* sense that a tape would be flagged when an issue occurs ( and it moves to another tape) as maybe a ‘safety of data issue’, but if that’s how it works, then that’s how it works ;)  I’ll try to see if I can track down when/why the tape issue is happening if it continues as we have had some issues with our drives (that have been remedied)