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FAQ - Wrong tape used

Created: 18 Nov 2010 • Updated: 19 Nov 2010 • 2 comments
pkh's picture
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Q. Why did BE use tape from a media set which is not targeted by the job?

A. When BE needs a tape to write to, it will first search for it in the following media set in the sequence listed below

1) the targeted media set

2) the scratch media set

3) any other media set

This is by design and is to ensure that the job completes successfully.

This problem will not occur if the Overwrite Protection Period (OPP) of the targeted media set is set correctly.  The most common mistake is not to cater for the time the job needs to complete.  The OPP starts from the end of the job, not the beginning.  Suppose the OPP is set to 1 day.  If your daily job is set to start at 10 p.m. and it takes an hour to complete, then the tape will be write protected until 11 p.m. the next day.  When the job runs again tomorrow at 10 p.m. the tape is still write-protected.  If the OPP is set to, say, 22 hours, then the tape can be overwritten and BE does not need to look for tapes from other media sets.

For a fuller understanding of how OPP and AP (Append Period) works, read the following article

http://www.symantec.com/business/support/index?page=content&id=TECH5459

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pkh's picture

A recent discussion brought out the fact that BE will also grab tapes from other media sets if there are insufficient tapes in the targeted media.  For example, you allocate 1 tape for the  job, but the data now needs two tapes and you forgot to add more tapes to the targeted media set.

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dl2rcf's picture

Hello,

I am referring to this article and partially to http://www.symantec.com/connect/forums/backup-job-taking-different-media-set

I am the admin of a flight library (no flight data may ever be deleted) so I also put the OPP (overwrite protection period) to Infinite - Do not Overwrite.

1. I also have set the option "Settings for media management" to "Overwrite recyclable media contained in the targeted media set before overwriting scratch media". BE2010 R3 SP2 does not seem to respect that setting (at least sometimes), since it grabs tapes from the scratch media set even though there are 10+ free media in the targeted media set.

2. Like the man from the mentioned thread "PCAU", I would strongly prefer a failed media job over "writing to some tape out of the assigned ones". There is a reason for this: If You handle NATO classified data with the tapes, always new tapes get "soiled" and You have to keep record of them to destroy them properly afterwards. This is way more work than a nicely sent message of a failed backup job.

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1. Why is BE2010 using scratch media as described above?

2. Is there an alternative (setting/ BE version) that has the option "prefer failed job over grabbing tapes from somewhere else"? Is partitioning a possible solution.

 

Many thanks for replying to this old thread and with best regards,

 

 

Ruben

 

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