How to configure which Tape is used

You could partition your library, and create separate jobs for each day of the week

or

From Tools\Options\Media Management, verify that "Use overwriteable media in the target media set before scratch media" is selected  and that either Full or Partial protection is selected

Set the OPP for the daily media set to 6 days

Make your daily job Overwrite only

It is very likely that your Tue. job is writing to your Monday's job because it is set to append.  Change the job to overwrite and set the AP of the targeted media set to 1 hour.  With a short append period, the next job cannot append to this tape.

Since you are using a library, you should not be too concern about which day's data goes onto which tape.  With a tape library, it is better to let it and BE manage your tape for you, rather than you managing the tapes.  See my article on this subject.

https://www-secure.symantec.com/connect/articles/must-mondays-backup-be-monday-tape

Thank you for your answers.

@pkh good article. I understand, at my actual configuration BE will always take the same tape until it is full. Then it will take ne next tape.

If i set the AP to 1 hour the next day BE will take another tape, thats clear to me. But next week on Monday, BE will look up de Daily Media Set and will not find a media to append. So I have to configure that it will be automatically overwritten and then I loose the incremental backup from last week.

My incremental Backup from MO - THU is about the size of 35 GB. If i dont use 1 tape each day, how many Tapes would you put in the Daily Media Set?

Thank you!

that it will be automatically overwritten and then I loose the incremental backup from last week.

How much retension you need for your incremental backups? And what is the type/capacity of your medias?  When you are taking full backup of those resources? Depending on these two things you can configure media set settings and overwrite options.

Depending on the backup size you mentioned in earlier post 1 media may be sufficient for holding 4 incrementals. (I presume you are using LTO 2/LTO 3 catridges). If you want one week retension on incrementals configure OPP as 10 days and Append period as 4 days for your Daily Media Set. Select Meida Overwrite option as Overwrite Recyclable media in the target media set before overwriting Scratch Media. Job should start as Append to media, Overwrite if no appendable media found. With this configuration 2 medias only will be used for daily incremental backups.

Regards....

Yes i have LTO 3 Catridges. Every Friday I do a fullbackup and at the last Saturday of the month i also do a fullbackup (monthbackup)

My incremental backup has the size of max. 40 GB uncompressed. If i look at de Datasize at the tape ist shows 25 GB. So I am able to get all the 4 incremental backups on one tape.

1 week retention is okay (actual week and week before). Good.

The Weekly Media set contains 4 Tapes. The fullbackup is about 120 GB on tape.

The full weekbackups on every Friday should be written one week a tape. Week one Tape1, week two Tape2 and so on.

For example I can set the OPP to 4 weeks or may be 5 weeks?, i dont know and the append period 6 days. Is that correct?

Assuming that you can fit your full backup and incremental backups onto one tape,  You are correct in setting the AP to 6 days.

You would set your full backup to overwrite so that it would always use a new tape and all your incremental backups will be set to append which will use the tape that was written to by the full backup.

OPP is calcalculated from the end of the last job to write to the tape.  In your case, it would be calculated from the end of your Friday incremental job, so you have to set your OPP accordingly so that there is always an overwriteable tape when the full backup job begins.  Since you have 4 tapes, your OPP should be set to 3 weeks.

For example I can set the OPP to 4 weeks or may be 5 weeks?, i dont know and the append period 6 days. Is that correct?

You want each weekly full backup onto a seperate tape. So, Append period None also will work without any problem. You can also give anything less than 7  days. As you have 4 tapes a little less than 4 weeks OPP will be perfect for Weekly media set.

For your Daily media set you can use the settings given in my earlier post as you want one week retension on those.

Regards....