Path: utzoo!mnetor!uunet!portal!cup.portal.com!th
From: th@cup.portal.com
Newsgroups: comp.sys.amiga
Subject: Re: Large hard disks for Amiga
Message-ID: <3822@cup.portal.com>
Date: 11 Mar 88 06:01:47 GMT
References: <7541@oberon.USC.EDU>
Organization: The Portal System (TM)
Lines: 27
XPortal-User-Id: 1.1001.2826


I haven't found ANY limitation re: the size of a hard disk one can place
on the Amiga (yeah, I'm the guy with the > 1GB Amigas).

HOWEVER, there *IS* the brain-damaged 50MB partition size limitation on
the Amiga which totally prevents the Amiga being used in any real
application by any of my customers.  My customers do NOT have or use the
"toy" 200 record or memory-resident DBMS products which seem to be
proliferating nowadays.

So where does the 50MB limit come from?  Simple.  Get out your calculators.
Look at the format of the root block: there is a list of 26 "pointers" to
the bit map pages.  Each bitmap "page" has 127 longwords of bits and one
longword of checksum.  Each longword has 32 bits.  So: 26*127*32 is the
LIMIT to the numbers of sectors AmigaDOS can handle on a hard disk.

Until this LIMIT is removed, the Amiga's filesystem is as BAD as the 32MB
limit on MS-DOS partitions.

100MB and larger data bases are NOT unreasonable.

Partitions are ludicrous.  Do YOU have partitions on your mainframes?

With a bank of Maxtor XT2190s on each Amiga, the limitation is crippling.

WHY isn't the list of bit maps an open-ended chain?  Haven't heard that
the alleged "Fast File System" (FFS) will correct this glaring deficiency;
does anybody KNOW if it will?