krueger@tacvax.mdcbbs.com (02/08/90)
Does anyone out there have any experience (good or bad) with the EPOCH-1 product??? We have approximately 50gb of diskspace on SUN/ULTRIX/HP/APOLLO workstations. Will the EPOCH-1 work for me or is there another product that I should investigate? We are examining 8mm subsystems at this time too. I will post results if there is any interest. -- +----------------------------+---------------------------------------------+ | Ken Krueger | Voice: (714) 952-6151 | | McDonnell Douglas M&E | | | Internal Systems Support | Internet: krueger@tacvax.mdcbbs.com | | 5701 Katella Avenue | UUCP: uunet!tacvax.mdcbbs.com!krueger | | Cypress, CA 90630-5099 | PSI: PSI%31060099980024::KRUEGER | +----------------------------+---------------------------------------------+ | Be nice to me, or I'll tell my uncle Freddy... Sweet dreams... | +--------------------------------------------------------------------------+
urban@randvax.UUCP (Mike Urban) (02/10/90)
In article <608.25d144b3@tacvax.mdcbbs.com> krueger@tacvax.mdcbbs.com writes: >Does anyone out there have any experience (good or bad) with the EPOCH-1 >product??? We have approximately 50gb of diskspace on SUN/ULTRIX/HP/APOLLO >workstations. The Epoch-1 is a good product if you have a lot of disk space that you expect to access only occasionally (system source code, for example). In its spare time, it migrates files from the magnetic disk to WORM (or, now, erasable optical) drives and doctors the inode so that the data can be found when needed. This gives a substantial reserve of space on the magnetic disk that can be freed quickly when there is a shortfall; if even more space is needed, magnetic files are `staged' to WORM in real time. All the software seems to work well; the system is generally transparent (typically used as an NFS server), although someone who does not know what is going on behind the scenes can make a mess of things. Our problems come in because we have just one WORM drive, when there is a demand for data from more than one WORM cartridge; the system goes into an inevitable swap-'til-you-drop dance in the WORM jukebox and the poor processes trying to access those files wait for the dance to complete. We had one case where errant shell scripts on multiple NFS clients attempted to uncompress a huge file from the WORM, and the poor Epoch kept trying to write files out to another WORM cartridge to make room for the result... if you anticipate accessing files from optical disk frequently, you should consider getting additional optical drives. Epoch's service people are knowledgable and responsive. We have particular problems because our machine is in a classified area and the Epoch folks cannot call it up remotely to diagnose problems; they have performed bravely under these circumstances. We have had more than our share of problems with the SCSI drives, but Epoch claims that they were apparently shipped some bad drives from Maxtor, and the problem has since been solved; everything else has been pretty solid. Epoch's backup software is particularly well designed. Our operators complain because it `takes care of too much stuff automatically', and that makes them nervous. There are some problems, generally along the theme of `I would rather do it myself.' There is no C compiler, so porting your favorite local software is impossible. The system keeps track of optical and magnetic disk (and tape) volumes with an Ingres database, but none of the details of that database nor any operation information is documented by Epoch; you must rely on their front-end programs for all operations. This is unfortunate when you want to do something a little out of the ordinary (as, `I mislabeled that WORM volume; please forget all about it'). On balance, however, we have been pleased with the product and are considering getting another for our unclassified systems. -- Mike Urban urban@rand.ORG