From: darkstar@pecan.cns.udel.edu (The Janitor Of Anarchy)
Newsgroups: comp.os.msdos.apps,comp.bbs.waffle
Subject: Re: A Poor Stacker application
Date: 17 Aug 92 18:10:22 GMT
Organization: The Green Circle Of Vengence

In article <ygumPB5w165w@dogbox.acme.gen.nz> dogbowl@dogbox.acme.gen.nz (dogbowl) writes:
>phil@miracle.com (Phil Hill) writes:
>
>> andyross@infopls.chi.il.us (Andrew Rossmann) writes:
>> >  I run a Waffle BBS, and recently tried Stacker on my news partition. I
>> >was hoping for big gains since everything is pure text.
>> >
>> >  The result? About 1.5:1 compression.
>> >
>> 
>> Not what I'm getting
>> 
>> SCHECK - 2.01, (c) Copyright 1990-92 Stac Electronics, Carlsbad, CA
>> 
>> Volume in drive E is NEWS
>> 
>> No errors found
>> 
>> Stacker Drive Statistics:
>> 
>>                  Stacker Drive             STACVOL File
>>                  Drive E:                  E:\STACVOL.000
>>                  ----------------------    ----------------------
>>   Total Bytes:     105,136,128                52,570,624
>>   Bytes Used:       50,733,056 ( 48.3%)       11,471,360 ( 21.8%)
>>   Bytes Free:       54,403,072 ( 51.7%)       41,099,264 ( 78.2%)
>> 
>> Stacker Drive Compression Ratio = 4.4:1
>> Projected Bytes Free            = 54,403,072
>> 
>> - - - -
>> 
>> If I put another 50MB in the drive, it would eat another 11MB of real
>> disk, leaving 30MB free but unusable (this is the 8K cluster problem).
>> 
>> But Stacker has an option to compress and re-claim this space, which
>> will give you 30MB of free space...
>> 
>> The final result: 105MB of news on 22MB of disk.  I'd say it's worth it!
>> -------------------------------------------------------------------------
>
>Don't bank on it. Stacker can tell *BIG* lies about compression ratios.
>I thought that I was doing quite well when scheck reported 400Mb being 
>compressed into 86Mb of actual space, but when I added up the file sizes 
>using Xtree, I found that it was actually 134Mb.  This was happening on a 
>213Mb partition.
>Now that I know that the reports are unreliable I keep a close eye on 
>what it says. 
>
>Ideally the cluster size needs to be around 256 or 512 bytes.
>I'd prefer to keep using Stacker, as I went and bought the coprocessor 
>card to speed things up. Anybody got ideas on tweaks??
>
>
>dogbowl at The Dawghaus BBS  ( +64 6 357-9245 )
Well, Stacker isn't really to blame, you are *8).  The problem is that
you're allowing Stacker to lie to you.  What you need to do is run 
SDEFRAG with the /R and /G options.  The /r option tells Stacker to 
recompress the data, and the /g option tells Stacker to change the size
of the Stacker drive.  It doesn't physically change the drive's size, 
but what it does is it changes the drive ratio.  Also, what it does is
change it to the actual ratio that scheck reports, not the ration 
everyone hopes they get!!!.  In other words, if you think you're getting
2.0:1.0 but scheck reports 1.3:1.0, then you need to change the drive
ratio, so you actually know how much space you're getting...

Now try that out, and see how close Stacker and XTree are!


	--Jerry

dd>


-- 

Jerry Alexandratos           | "Choosing a president is like going to
darkstar@freezer.cns.udel.edu|  an adult bookstore...  It's picking 
darkstar@bach.udel.edu       |  the dildo that will hurt the least!!!"
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