Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!blake!aragorn
From: aragorn@blake.acs.washington.edu (Michael Owen)
Newsgroups: comp.sys.apple
Subject: Re: Problems with large files & large sub-directories
Summary: How much is too much?
Message-ID: <1828@blake.acs.washington.edu>
Date: 1 May 89 08:29:55 GMT
References: <8904301302.aa27400@SMOKE.BRL.MIL>
Organization: Broken Blade Software
Lines: 62

In article <8904301302.aa27400@SMOKE.BRL.MIL> IRPGMR7@OUACCVMB.BITNET writes:
>One last general little thing:  What are the acceptable limits in number
>of files stored in a directory??  (I've got every file from Apple2-L
>stored in a single subdirectory in text file format, and many many programs
>I get seem to crash when they try to read the directory and display it.  I
>know, I should try store that many files in a subdirectory, but I'm working
>on getting them converted to regular program files for a local Apple Users
>Group.)

I recently made some rather unscientific tests on how many files a
subdirectory can realistically hold.  In writing my own BBS, I've yet to
decide on a method of saving a user's e-mail.  One option I came up with was
to use a Unix-like method and create a subdirectory for every user in the
e-mail directory, and store a user's mail there.  I've got a maximum userlog
size of 500 users, so I created 500 subdirectories, named user.0001-user.0500.

Then I copied three files to directories 1, 50, 100, 250, 300, 400, 450, and
500, and read them into an array using ModemWorks' & FILES command.  The drive
I used was an Everex 20D SCSI, with a rated access time of 65 ms.  The times
to perform the operations were as follows:

Full pathname: /ea/broken.blade/email/user.nnnn

Filename	Time (approximate)
----------------------------------
user.0001	< 1 sec
user.0050	< 1 sec
user.0100	~ 1 sec
user.0250	~ 1 sec
user.0300	~ 2 sec
user.0400	~ 2 sec
user.0450	~ 3 sec
user.0500	~ 3 sec

The directory file itself (/ea/broken.blade/email) was 39 blocks big (500
files/13 files per directory block).  When I tried a catalog of the drive with
Copy II Plus v8.3, it only read in 191 files; using Cat Doctor, it simply
returned "This directory is too large."  Even when I pared down the directories
to just 50, Cat Doctor still complained "This directory is too large."; Copy
II Plus read them in just fine.

Of course, ProDOS puts no limits on the number of files a subdirectory can
hold, besides that of having enough disk space to store the directory file.
However, from the tests above, and my experiences with various utility
programs, I think there is a practical limit to just how big you should make
your subdirectories.  ProDOS allows 57 files (I think that's the number) to be
stored in the volume directory (assuming a 'standard' version of ProDOS; i.e.,
one that hasn't been modified to use additional volume directory blocks).
This should be enough for any reasonable user to organize his or her files in
an orderly manner.  But, I digress; I certainly don't want this message to
degenerate into a discussion on the right way to organize one's hard drive.

In short: use your directories wisely!

>David William Wrage  a.k.a.  The Frenchman

______________________________________________________________________________
       />    The Broken Blade           Aragorn III (Michael Owen)
      /< ________ ______________        aragorn@blake.acs.washington.edu
C=====[*>_______/|______________>       Starfleet HQ: (206) 783-5589
      \<                                3/12/24 8N1 24 hrs - A ModemWorks BBS
_______\>_____"Ai na vedui!"__________________________________________________