Path: utzoo!attcan!uunet!ginosko!usc!ucsd!ucbvax!hplabs!hpfcdc!steve
From: steve@hpfcdc.HP.COM (Steve Taylor)
Newsgroups: comp.sys.hp
Subject: Re: Un-partitioning Hard Disk on HP 9000/300 Series
Message-ID: <5570273@hpfcdc.HP.COM>
Date: 19 Aug 89 01:08:56 GMT
References: <1989Aug18.014354.189@cs.rochester.edu>
Organization: HP Ft. Collins, Co.
Lines: 44

} > While we're on the subject of disks, I see that BASIC 5 now supports a
} > Hierarchical File System.  How much overhead does this consume on the disk?
} As I recall, it requires 512 bytes per [BASIC-type] file.
} > And does it eliminate the requirement that files be stored on contiguous
} > blocks?
} I think so.

From "Installing and Maintaining the BASIC 5.0/5.1 System", p2-6:
(adapted slightly)	Disc Size	Approx. Overhead
			270K floppy		44%
			640K floppy		22%
			720K floppy		18%
			 55M hard disk		 6%
			130M hard disk		 6%
Of course, this doesn't include the size you're interested in, but the trend
is clear.  The 512 bytes per file applies to typed files.  5.0 also added an
"untyped" data file which does not have this header.  Yes, it eliminates the
requirement that files be contiguous.  Some other considerations (from p2-5
of the above reference):

Feature:		HFS:			LIF:

Directory		Hierarchical		Single directory
structure		(multi-directory)	on each volume
                        structure

Multiple systems	HP-UX, BASIC, and	BASIC and Pascal can
on same volume		Pascal systems can	share a disk
			share a disk

Extensible files	Files are extensible	File length is fixed 
			(when a file would	
			otherwise overflow,
			the system automatically
			adds space to it)

Access times		Generally slower	Generally faster
			than LIF		than HFS

TRANSFER		Not implemented as	True background process
			a background process	and high data rates

Overhead required	Requires more 		Requires less overhead
			overhead than LIF	than HFS