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Overwrite job requesting new media after writing 25% of tape capacity

Recently, my nightly backup jobs have been failing due to cancellation (automatic cancellation due to elapsed time).

A couple of hours into the job, the tapes are ejecting with a request for new media:

Please insert overwritable media into the drive.

Overwritable media includes scratch, blank, and recyclable media. Please note that depending on the current Media Overwrite Protection setting, imported and allocated media may be overwritable as well. Consult the online help for more information on overwritable media.

The job is an overwrite job, and Media Overwrite Protection Level is set to None. The Overwrite Protection period of the media set is 1 hour, with Infinite Append.

The tapes are LTO-2 with a capacity of 200 GB. The nightly job is writing ~53 GB to tape before requesting new media.

This happens even following a long erase of the media. The media properties indicate that is Overwriteable, but not Appendable (media full).

Can anyone advise why the tapes are being marked as full after an overwrite job that writes only about 25% of the tape capacity?

2 Replies

Re: Overwrite job requesting new media after writing 25% of tape capacity

When you set your OPL to None, the OPP does not apply which means that your tape can be overwritten at any time.  You have to set the OPL to either Partial or Full to get data protection.

Your problem could be either due to the job appending to the tape or your job is compressing data which are already compressed and you end up with more data than you have started with.

The other possibility is that your tapes or your tape drive is bad, thus causing a lot of bad unwritable areas on the tape, reducing the tape capacity.

Re: Overwrite job requesting new media after writing 25% of tape capacity

Since that tape is showing in BE as "(media full)" I doubt this has anything directly with to do with your BE settings.  But I do agree with PKH's suggestion to NOT use Overwrite Protection = none, as a general best practice.

BE writes to a tape until the tape drives tells BE that the tape is full.  Once the tape is marked as full, obviously BE cannot use it and will eject it.  You might have some bad media, which can be tested by trying other media.

I suspect you have a very clogged tape drive head.  I suggest running vendor diagnostics on the drive and working with the hardware vendor.  This is somewhat hard to diagnose when the heads are only partially clogged, but yours sounds very bad if you are only getting 25% of the native capacity.

http://www.symantec.com/docs/TECH193200