Single tape for monthly backup

Hi everybody!

 

I've the following scenario:

I've 10 servers which are backed up with the following schedule:

Daily -> Incremental back up, from monday night to friday night.

Weekly -> Full back up every saturday night (this job is superseded by monthly job)

Monthly -> Full back up every first saturday night of each month

 

I have 3 media sets created: 

Daily -> Overwrite protection = 6 days; Append period = 1 day

Weekly -> Overwrite protection = 4 weeks; Append period = 6 days

Monthly -> Overwrite protection = 1 year; Append period = 6 days

 

Overwrite protection level is set to "Partial with user prompt"

 

I don't mind what tapes the daily and weekly backup jobs use, as far as they are taken from the correct media set.

What I can't get to do is that monthly backup takes a single tape. When I had "Overwrite protection level" set to "None", BE2012 would take any tape from the other media sets and make it a monthly tape, erasing all data in it. 

Then, I changed "Overwrite protection level" to "Partial with user prompt", and now it only took tapes from monthly media set, but it used one tape for each job and it is stucked in one job asking for more tapes when it has plenty of space in the rest of the tapes of the media set.

 

What I want to achieve is that the monthly backup is made on a single tape, or two, depending on capacity.

How can I get to do this? Why BE2012 asks me to insert one tape, when it has plenty of space in tapes that are on library?

 

Thanks!