On 10/28/2014 01:04 PM, Alan Brown wrote: > > Block devices may be block devices, but a tape drive is a character device.
Oops. Works either way, disks are char aka "raw" devices too. > People coming from a tape environment tend to see tapes (volumes) as > something you use for a pool of clients or filesets, because changing > volumes is NOT trivial, the tapes are only reated for a limited number > of load cycles and you can only access one volume at a time. > > If you have more tape drives you can access more volumes simultaneously, > but changing volumes is no less difficult/timeconsuming. As is changing disks. Skipping from one tarball to another on tape may take much longer, but that shouldn't make any difference to the higher-level code. There is no reason to see file volumes as dedicated to a client AFAICT; those who want it can do pool per client and volumes per pool -- works with tapes just as well. Yes, in general you can access multiple files on the same disk simultaneously. I don't expect that a backup application streaming data to or from that disk would -- or should -- actually do that, for any number of obvious reasons. Which is why I'll never understand the tape/disk dichotomy. (As an aside, bacula, specifically, seems to force you to use different Media Type for each physical device so I don't get how it would work with multiple drives in the same jukebox, either -- thankfully I don't need to.) -- Dimitri Maziuk Programmer/sysadmin BioMagResBank, UW-Madison -- http://www.bmrb.wisc.edu
signature.asc
Description: OpenPGP digital signature
------------------------------------------------------------------------------
_______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
