Rebuild catalog - Problem with one of the tapes in Retrospect 9 or higher for Macintosh Posted 21 hours ago · Edited 9 hours ago by DavidHertzberg Add link to Ars Technica post In second paragraph; the post recounts AIT bugs in Retrospect 6.1. Add to first paragraph remark that EMC EOL'ed Retrospect Mac. · Report reply oslomike, Based on announcements made at the time of its 2019 acquisition by StorCentric, Retrospect Inc. had about 20 employees—with most working from home. It has never in its 30-year history had any hardware-related capability. In fact before Dantz Development Corp. was acquired by EMC in 2004, Dantz used to get driver source code from the manufacturers of various kinds of tape drives—and hire contractors to rewrite that code so it would interface with Retrospect Mac and Windows. That's how Retrospect at the time of its acquisition by EMC had cornered 90% of the market for Mac backup software, and more Windows users than Mac users. (EMC end-of-lifed Retrospect Mac after disk-destination Time Machine was released.) Sometimes the manufacturer's driver code would have bugs, and sometimes the contractors would introduce bugs—which is probably why Retrospect Mac 6.1 can't use the hardware compression capability of my HP DAT72 tape drive. A lot of Retrospect's terrible reputation among IT old-timers, which they've expressed to me in my 4-year-old Retrospect thread on the Ars Technica Mac forum, results from the defects of its tape drivers—note that the linked-to post says another app's AIT driver worked better. It sounds as if there might be a bug in the Retrospect Mac 10.5 AIT driver code, although it might use an AIT driver provided by Apple in later versions of Mac OS X. Your idea of copying your AIT Tape Backup Set to an LTO tape using Retrospect Mac 6.1 is excellent, because LTO is an industry-standard tape format with less flexibility for drive manufacturers.