Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!cbmehq!cbmdeo!adspdk!hclausen
From: hclausen@adspdk.UUCP (Henrik Clausen)
Newsgroups: comp.sys.amiga
Subject: Re: Looking for a disk cache
Message-ID: <186ed84b.ARN1370@adspdk.UUCP>
Date: 28 Dec 90 08:58:35 GMT
References: <1990Dec21.163546@lemur.inria.fr> <640@tnc.UUCP>
Reply-To: hclausen@adspdk.UUCP
Followup-To: comp.sys.amiga
Organization: Graffiti Data
Lines: 56

In article <640@tnc.UUCP>, GUY GARNETT writes:

> In article <1990Dec21.163546@lemur.inria.fr> colas@lemur.inria.fr (Colas Nahaboo) writes:
> >I am looking for a disk cache (preferably for floppies, PD or commercial) with
> >these features:
> >
> >- able to buffer whole track when accessing one sector.
> >
> >- buffering writes.
> >
> >- allocating buffers in Fast Ram.
> >
> >Or other nice features (automatic bufferring of headers, do not buffer "big"
> >reads...)
> >
> >Does FaccII or BlitzDisk have these features? 
> >Do they work with FFS?
> >Did you use them?
> >Did they trash your disks ? :-)

   I used BlitzDisk for quite a while, when I ran the old ConfMail that
would scan a N file message directory N*N times! BlitzDisk sure ran cool on
my harddisk, never trashed anything. Used it on floppies as well, but
having a HD, floppies tend to collect dust :-)

   It doesn't buffer by track, but by sector. Meaning you will have to read
a sector once to have it in the buffer. In my experience, this is quite
reasonable, though not really optimal if you have lots of memory to burn. 

   I wouldn't run it with buffered writes. Suppose you crashed with the
disk in an uncertain state?

   Buffers go to Fast ram by default.

   BlitzDisk II works with FFS - I'm quite sure FaccII doesn't.

> Only Gripe: FaccII flushes the cache whenever a disk is ejected, even
> if something still has files locked on the disk (it would be nice if
> it kept the disk's cache around until I was all done with the disk).

   You can ask BlitzDisk to only buffer directory blocks and file headers -
real handy for my purpose. It will avoid buffering large files, and can be
set to hold stuff when you eject a disk. Everything is setable on the fly,
and in general, it does about the same as FaccII. I've heard that in some
details, Blitzdisk is a bit smarter, but not having FaccII, I can't tell
for sure. I think FaccII is a much larger executable, though.

   You'd be pretty well off with BlitzDisk.


                                                 -Henrik

______________________________________________________________________________
| Henrik Clausen, Graffiti Data | If the Doors of Perception where cleansed, |
| ...{pyramid|rutgers}!cbmvax!  | Man would see Reality as it is - Infinite. |
\______cbmehq!adspdk!hclausen___|_________________________________W. Blake___/