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From: jeh@sisd.kodak.com (Ed Hanway)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Virtual Disk (Was Re: Files larger than available memory.)
Message-ID: <1990Oct9.122616.13048@sisd.kodak.com>
Date: 9 Oct 90 12:26:16 GMT
References: <1088@ucsvc.ucs.unimelb.edu.au> <409@tlvx.UUCP> <1124@ucsvc.ucs.unimelb.edu.au>
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In article <1124@ucsvc.ucs.unimelb.edu.au> U3364521@ucsvc.ucs.unimelb.edu.au (Lou Cavallo) writes:
>My idea:
>
>A virtual memory fixed disk (VFD:) would be a file structured RAM disk device 
>like RAD: that would set up on it a set of memory swapping buffers for files.
>The VFD could be mounted to (say) a 100 Mbyte virtual allocation but only use
>the user selected amount of RAM for the in memory buffers.

You can do this today.  Just mount a hard disk partition and use AddBuffers
(or equivalent) to select the size of the buffers.  No special handler
required.

This idea's not completely dead, though.  There are a few things that could be
done to optimize a partition for temporary file use.  First, vary the size
of the buffers used based on current usage, free RAM, etc. Second, don't
write changes through to the disk until pages are flushed from RAM.
With these features, either as options to the FastFileSystem or as a separate
file system altogether, you could reserve 10-20M of disk space for a fast T:
partition optimized for temporary storage.

Comments? Suggestions? Volunteers?

Ed Hanway
uunet!sisd!jeh