Overwrite policy issue

[Twa]

As we're a small sized business with little data to backup, we've decided to use one tape for each day of the week, to keep at least one week of history. I've set the overwrite protection period to 5 days, so in case someone inserts an incorrect tape, there is no data overwritten or written on an incorrect tape.

This works quite alright, except for a few cases. Sometimes, on full tapes, the backup never completes and the tape is ejected, and backupexec keeps asking for a new media. When the tape is re-inserted, the tape is immediately ejected again and BackupExec says the media is overwrite protected (sounds alright, since the overwrite period is 5 days).

I think the problem is that BackupExec starts overwriting one old backup set on the full tape, but when it turns out the new backup data is actually larger than the space on the tape + the overwritten backup set, it ejects the tape, because it's full, and waits until the next tape is inserted.

What I want it to do is simply erase enough data, simply erasing multiple backup sets, until there is enough space on the tape to fit the entire backup set.

I've tried multiple backup set settings, but have so far been unsuccessful to get this done.

Anyone have any idea how to achieve this?

[pikes]

"Sometimes, on full tapes, the backup never completes and the tape is ejected, and backupexec keeps asking for a new media."

By "Full tapes" do you mean tapes that are still in overwrite protection period and are appended to the maximum size of the tape? In other words, someone inserted the wrong tape and that tape is still under an overwrite protection period and also still under an append period (I'm assuming the media set has the append period set to infinite). So, when the backup writes to the tape, it fills up the rest of the tape then asks for a new tape since it's full?

"What I want it to do is simply erase enough data, simply erasing multiple backup sets, until there is enough space on the tape to fit the entire backup set."

I've read this several times and I still don't understand what you're trying to say here. There's no way for backup exec to "know" how much data a backup will use before it completely runs through so there's no way to "simply erase" enough data to make room for the new data.

[Twa]

By full tapes I mean tapes that have been appended to the maximum size (or almost the maximum size), and are not in overwrite period.

It writes part of the backup to tape and overwrites apparantly part of the tape, but instead of overwriting enough data to fit the backup, it ejects the tape and asks for a new tape halfway through the backup.

What I want it to do is just fit the backup on one tape, overwriting as much old data as needed. I hope that clarifies it for you.

[pikes]

Ah, I see. So your media is not in an overwrite protection period... then the backup starts overwriting the media, but stops overwriting the media in the middle of the backup saying it's full and asks for a new tape. How big is a completed full backup? How big are your tapes? If you have enough room on the media to do a full backup, and the media's overwrite protection period has expired, you should not have any problems.

If all else fails you can set up your job to point to a device pool which could include a backup to disk folder to finish the backup. This may not be a practical solution at all but it's available to you. It may also be useful for troubleshooting purposes.

[Ben_L_]

Twa,

Check your job properties on the Device and Media section, is the job set to "Overwrite Media" or "Append to media, overwrite if no appendable is available".

The default setting is the 2nd option.  You may want to change this to the first option.  This way it will always do an overwrite of the media and not append to any of it.   There is not any way to get the backup to just ovewrite enough room on the tape that it needs, it's either all or nothing.  With this change though, if a tape is not changed out it will prompt to insert media until an overwritable take is inserted.

[Hywel_Mallett]

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Twa wrote:

What I want it to do is simply erase enough data, simply erasing multiple backup sets, until there is enough space on the tape to fit the entire backup set.

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As others have said, this can't be done. When a job has filled a tape, any subsequent tapes used for the job must overwrite.