SYSTEM%HYCAD5@engvax.scg.hac.COM (09/17/87)
We are looking at several vendors who appear to have a VHS backup capability (backup VAX/VMS data onto a standard VHS tapes as opposed to reel mag tape)? Anybody have any experience/suggestions with this approach Ed Shi Hughes Aircraft Company (714)759-2286 shi%hycad5@engvax.scg.hac.com thanks ahead of time
OBERMAN@LLL-ICDC.ARPA ("Kevin Oberman, LLNL, 422-6955, L-156", 415) (09/22/87)
> We are looking at several vendors who appear to have > a VHS backup capability (backup VAX/VMS data onto a standard > VHS tapes as opposed to reel mag tape)? Anybody have any > experience/suggestions with this approach One of the systems here is running the DIGI-DATA system. It costs about $7K with UNIBUS controller and software. Less if you have a Pertec formatter available. So far, so good. It does the BACKUP of a 456 MB disk in about an hour and 15 minutes. A single tape hold about 1.2 GB. This is because we are driving it with a 750. With a faster processor we might reach the specified 2.2 GB. Since it has only been running for a month, I don't know about the shelf life of the tapes, but I wouldn't try it as an archive system. Just paranoid, I guess. Because it does not stop-start well, it writes `white space' if the processor can't keep the buffer loaded. This means that a fast CPU is needed to keep the drive from wasting tape. And CRC on most systems would be a disaster. Esp. on a uVAX. I suspect that a uVAX BACKUP with CRC would result in about 100 MB per tape. The unit does have hardware CRC. I'm very interested in hearing about other's experiences as I want to get more systems in the near future. I've heard that systems based on the DAT tape format will be forthcoming within a year. And these are supposed to be 5.25 form factor. They should be able to fit in the space for a TK50/70. Doesn't a 2 GB tape on your uVAX sound nice? R. Kevin Oberman Lawrence Livermore National Laboratory arpa: oberman@lll-icdc.arpa (415) 422-6955 Disclaimer: I am not endorsing any product. I work for Uncle Sam and to do so would make him upset. Neither my employer nor myself can take resposibility for the accuracy of this information. I believe it is correct, but if it's not I can only say "Sorry". I'm a rotten typist and a worse speller, so forgive any silly errors.