Marc Muehlfeld wrote:

Hi,

I have two sets. The first is for daily backup and the second is a level 0
dump that runs every first saturday of a month. The tapes of this set we
store for one year offsite. After that time the tapes are overwritten. But
the tapes from January and July were set to no-reuse and will never be
overwritten (digital preservation).

Are index files of tapes set to no-reuse removed after 12 month (tapecycle
12 tapes)? Or do I have to keep them somewhere else to have a comfortable
recovering using amrecover?

No, the index files are not erased after a dumpcycle.
They are only erased when the tape is overwritten
or when you do "amrmtape".