From: KZUPAN@LSTC2VM.stortek.com Subject: Re: ********* Let's ! ***************** Date: Mon, 17 May 1993 15:34:50 GMT
In article <raynor.737133078@ash.cs.scarolina.edu>
raynor@cs.scarolina.edu (Harold Brian Raynor) writes:
>
>ins413j@mdw041.cc.monash.edu.au (Markfried Fellensiek) writes:
>> You've heard of virtual RAM, by swapping to disk,
>> How about virtual diskspace, by swapping to floppies?
>
>> Typically you'd have some daemon running... when
>> the freespace gets to below a threshold, the
>> daemon looks at the least recently accessed file and
>> gzip's it out to a blank disk, and tells the user
>> to label that disk with the current number: eg 45
>
>No, I for one wouldn't want be foreced when my disk was full and put in
>some disks. Actually just the system doing this automatically would
>really be of no help, you could easily type that command (there's no way
>that it could automagically change disks by itself).
>
>Now, tape might be a better answer, as it could be done unattended - in
>fact I had thought of such a thing. It would be pretty easy to
>implement in a script file actually (assuming Linux supports your tape
>drive, it doesn't support mine).
>
>> can you imagene havving an 80disk box sitting next to your
>> pc (an extra 115Mb) and only when you need to use
>> obscure files....
>> like:
>
>> man man
>
>> or:
>> man ls
>
>> or:
>> xmono
>
>Yes, I can imagine being in a hurry to get something done and being told
>- "Please insert disks 37-93 in order to restore your files" :-( Sounds
>like a nightmare to me!
>
>A better way to do this would simply be to gzip unused things and ungzip
>them when they are needed. While they would still be on the disk, they
>wouldn't take up as much space. Also if your DOS FS isn't full at the
>time you could also tar them to that without loosing the filenames/ etc.
>
>This would probably be relatively easy to implement in the background.
We use a similar system on our main frames known as HSM or Hierchial
Storage Manager. From my understanding of it, if a dataset (i.e. file)
goes unused for a certain amount of time it is archived to dasd, after
an even longer amount of time, if it is still unused it goes to tape.
When a user wants to use this dataset HSM goes out and retrieves the
dataset and restores it. If there is insufficient space however, space does
need to be made manually. It seems to be a pretty efficient system. I have
wondered what it would be like to implement it on a PC. I maybe wrong
but I do think there would be some people who would use it.
Kevin Zupan
Kzupan@lstc2vm.stortek.com