newbie@inmet.inmet.com (07/27/90)
/* Written 4:27 pm Jul 24, 1990 by bhatlas@pyrite.SOM.CWRU.Edu */
/* in inmet:comp.sys.mac.misc */
/* ---------- "VANISHED! 12 Mb on a 80 Mb Hard Di" ---------- */
The last thing I need is a shrinking hard disk...
My 80 Mb internal hard drive (on a Mac IIx) shows:
"66,137K in disk 12,600K free"
But when I catalog all the files (including the desktop)
I can only account for 56 Mb. I tried Redux and a couple of
disk cataloguing programs, and they all tell me the same thing.
Someone suggested I zap the PRAM, but that didn't help.
Where is the additional 12 Mb? HELP!!
/* End of text from inmet:comp.sys.mac.misc */
I must preface this by saying that I'm a rabbid IBM'er, and only read these
Mac groups for laughs. However, I think that I may know what is going on
here (I *do* have significant Mac experience - most of it painful; *PLEASE* -
let's not start any flame fests over it, ok?) Some things (believe it or
not) are common accross (almost) all computer systems...
Anyway, all disk systems allocate space with by means of some sort of
object (a cluster in IBM lingo) which are of some uniform size. This size
is usually something like 1024 or 2048 bytes (I believe it's 1k on the Mac,
please correct me if I'm wrong). Evey file on the disk *HAS* to be some
multiple of this size. So, a 732 byte file will occupy 1024 byte of disk
space, even though the Finder reports it's size as 732 bytes. If your
disk cataloging software is using the size as reported by the system,
the it too will get the "wrong" idea about how much space your files
occupy. In addition, the "free disk space" reported by the system is the
"true" amount of free space - i.e. it *DOES* take into account the fact
that your 732 byte file is using 1024 bytes of space.
Now, as you may be able to see, this is more of a problem if your disk is
full of many small files - more space is wasted on small files (proportionally)
than large ones.
One way yuo can check this out is to use the "Get Info" option in the finder.
Select a file (or group of files) and hit Command-I (or choose Get Info).
The dialog will report the file size (732 bytes in my example) and then
another number (1024 bytes from my ex.) "on disk". The first is the
acutal number of bytes in the file, the second how much it occupies on the
disk. Try it out and you'll begin to get an idea of how much space is
"useless" just because of the way file systems allocate storage.
This would be my first guess. Other good suggestions I've seen include
hidden files, or an over-grown desktop file (though 12MB is awful exessive for
a desktop...). Don't mess with zapping things
unless these things don't explain your trouble.
- Chris
>>>> Chris Newbold <<<< | Murphy's Law: |
Intermetrics, Inc | "Don't mess with Mrs. Murphy!" |
Disclaimer: "All warranties expire upon payment of invoice."
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