From: "William H. Geiger III" <whgiii@invweb.net>
Date: Mon, 17 Nov 1997 12:01:29 +0800
To: Bill Stewart <stewarts@ix.netcom.com>
Subject: Re: RAM disks for temp files?
In-Reply-To: <3.0.3.32.19971116125402.007134ec@popd.ix.netcom.com>
Message-ID: <199711170351.WAA27712@users.invweb.net>
MIME-Version: 1.0
Content-Type: text/plain



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In <3.0.3.32.19971116125402.007134ec@popd.ix.netcom.com>, on 11/16/97 
   at 12:54 PM, Bill Stewart <stewarts@ix.netcom.com> said:

>At 01:27 AM 11/16/1997 +0100, Anonymous wrote:
>>> (Hint, temporary files all over the place.)
>>  For you old farts who have not been out in the real world for a
>>while, you should make note of the fact that the price of memory
>>has dropped, and it is now feasible to implement RAM disks to
>>store temporary files.

>I was using RAM disks on my 386 machines with Win3.1.
>Now that I've got faster machines with more RAM,
>I'm running Win95 and can't find a ramdisk program - 
>does anybody know where to find one?

>On Unix, you _could_ do things with temp files,
>but it usually made much more sense to structure your programs to use
>pipes, which means there's no temp file and only
>a few KB of RAM buffering in between each program.
>PGP's DOS heritage doesn't encourage this sort of programming, though the
>new design for one-pass processing may have
>made it either possible or unnecessary.

>On machines with real operating systems, designing a 
>ramdisk includes deciding whether to make it virtual memory
>that might get swapped if necessary, or nail it into RAM.
>Since RAMdisks are usually intended for increasing speed,
>it usually makes more sense to let the vm manager decide
>what pages to page out and what pages not to,
>but obviously if you're using it for security that's different.

>SunOS had the /tmpfs file system design which let you
>get hybrid behavior - temp files stay in RAM until
>they need to get swapped out to disk, and most programs
>delete them before that ever happens - really speeds up compiles. >From a
>cryptographic standpoint, it's not ideal, since occasionally your files
>would end up on disk, but they'd usually be safe.
>				Thanks! 

For OS/2 there is a very nice RAM Disk program called SVDisk. It allows
you to "lock" a portion or all of your Ramdisk to be non-swapable. Also
has multiple disk support, HPFS & FAT support, and various floppy format
support for VFloppies.

The initial VDisks must be set-up in the config.sys via the VDisk.sys
driver. After bootup the user is free to mount & unmount disks, format
disks, and lock and unlock portions of the VDisks.

I usally run a 8Mb HPFS VDisk Locked for a temp directory.

- -- 
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William H. Geiger III  http://users.invweb.net/~whgiii
Geiger Consulting    Cooking With Warp 4.0

Author of E-Secure - PGP Front End for MR/2 Ice
PGP & MR/2 the only way for secure e-mail.
OS/2 PGP 2.6.3a at: http://users.invweb.net/~whgiii/pgpmr2.html                        
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