On Sun, Jul 22, 2018 at 08:06:24PM +0200, Carlo Pisani via cctalk wrote: > thus DDS4, LTO2, DLT: which is the best tape?
If you even remotely care about your data, stay far away from DDS. In a previous job we used DDS3 tapes as system backup and restore tapes (since the machines could boot from them). Those were written at most once a month and in 1.5 years there I accumulated a nice stack of 'dead' (hard read errors) tapes. I think none survived more than half a dozen write cycles and they got read not much more. Generally, avoiding any helical scan tape technology (DDS, AIT) is probably a good idea on account of increased head & tape wear this causes. Personally, I have good experience with both DLT and LTO, both are linear scan technologies and IIRC are specified to last at least 1-2 decades given proper storage. Of course, you still want several generations and copies of your backups. Another thing to keep in mind: it is nice if your backup medium lasts decades, but what about the reader for it? Will that be available down the road as well and usable? And, not to forget: what format are your backups written in. Something standard like POSIX tar or some proprietary format used by some commercial software, which might have availability issues in the future. Kind regards, Alex. > > 2018-07-22 18:11 GMT+02:00 Jon Elson via cctalk <cctalk@classiccmp.org>: > > On 07/22/2018 10:52 AM, Chuck Guzis via cctalk wrote: > >> > >> On 07/22/2018 06:33 AM, Paul Koning via cctalk wrote: > >>> > >>> > >>>> On Jul 21, 2018, at 3:25 PM, Carlo Pisani via cctalk > >>>> <cctalk@classiccmp.org> wrote: > >>>> > >>>> ... > >>>> and what about magnetic-tapes? (e.g. DDS4, DLT, LTO2) > >>>> > >>>> which of them lasts for the most? > >>> > >>> I don't know specifically. I do know that plain old audio tapes may fail > >>> -- I have perhaps 100 cassettes recorded in the 1970s. Most of them are > >>> fine, but essentially all of them that are Fuji brand have failed utterly. > >> > >> Half-inch open-reel tape at 1600 PE density. Should be good for 50 > >> years at least. > >> > >> > > Well, you are one of the experts in this, but it all depends on storage > > conditions. Also, the extended-length tapes were too thin, and suffered > > from creasing and print-through. Badly stored, and you can kiss your data > > goodbye in less than 5 years. > > > > Jon -- "Opportunity is missed by most people because it is dressed in overalls and looks like work." -- Thomas A. Edison