Well I guess if you had caching turned on in the diskpool and then migrated to tape and then backed up the tape pool you would have three copies of your data at the same time. Caching isnīt always a good thing though so if you could set up a Diskpool for these logs and just backup the logs you spoke of to this Diskpoolpool and turned the caching on in this diskpool you would get the same result. Other than that I think that if a Tape fails during the Migration then the migration fails and the data wonīt be deleted from the cache(Committed to the DB) But maybe Iīm wrong.
