sandy@polari.UUCP (sandy fifer) (12/10/90)
I'd like to find out how magneto-optical jukeboxes behave when attached
to Unix systems. That is, how do they fit into the Unix filesystem, and
how do they look to users?
For example, if I want to gain access to a file on a certain cartridge,
do I have to use some command to ``load'' the cartridge, and then mount
it onto a directory? Or are the cartridges all mounted at the same
time, and the driver loads and unloads them appropriately, as I peruse
the corresponding directories?
Either of these approaches (and probably others) should be possible.
What do vendors actually provide? I'm primarily interested in jukebox
subsystems, rather than jukeboxes incorporated into turnkey NFS servers.
Thanks for any enlightenment you can provide.
Sandy Fifer sandy@polari.uucp
...!uw-beaver!sumax!polari!sandymark@hpcpbla.HP.COM (Mark Simms) (12/11/90)
Hewlett Packard's support of magneto-optical juke boxes allows transparent access to all surfaces in the system. All surfaces may be logically mounted at the same time. Whenever access is required to a given surface the correct disc is inserted into one of the drives. The advantage of this approach is that access is completely transparent to users, other than in terms of performance. The main disadvantage is that if a lott of accesses are made to different discs, then performance can be poor. Interestingly, the explicit load/unload commands can be constructed on top of this system if required. A load would cause an unmount of whatever was in the drive and a subsequent mount. An unload would cause just an unmount. If you really wanted, you could even add locking functionality so that only the loading user could unload or reload. Mark Simms ---------------------------------------------------------------------- Opinions expressed are my own and are not intended to be an official statement by Hewlett-Packard Company ---------------------------------------------------------------------- Name: Mark Simms Profession: Software Engineer Occupation: Research and Development Organization: Hewlett-Packard Computer Peripherals Division Unix-mail: mark%hpcpbla@hplb.hpl.hp.com ----------------------------------------------------------------------