[comp.sys.sgi] What's and "Extent File System"?

pwp@shamash.cdc.com ( HOUFAC) (09/21/89)

Can anyone tell me what an "Extent File System" is (compared to a "normal"
Unix System V file system).  I see it mentioned in nearly every SGI document
but I haven't been able to find and explaination of what the benefits are.

Thanks!  --Pete Poorman

kipp@warp.sgi.com (Kipp Hickman) (09/22/89)

The Extent File System is SGI's high performance filesystem running under
system V.  It is faster than the BSD filesystem, and tends to provide
contiguous files (up to a certain point).  There are man pages that describe
it at a certain level...The main thing to know is that it is not the AT&T
slow filesystem.

					kipp hickman
					silicon graphics inc.

mlj8e@dale.acc.Virginia.EDU (Michael L. Johnson) (09/23/89)

In article <643@odin.SGI.COM> kipp@warp.sgi.com (Kipp Hickman) writes:
>
>The Extent File System is SGI's high performance filesystem running under
>system V.  
>					kipp hickman
>					silicon graphics inc.
 Actually, didn't the extent file system come from SUN?
 


(804)-924-8607                   Michael L. Johnson
mlj8e@virginia.EDU               Pharmacology Dept.
uunet!virginia!mlj8e             Box 448; Univ. of Va.
mlj8e@virginia.BITNET            Charlottesville, Va. 22908

vjs@rhyolite.wpd.sgi.com (Vernon Schryver) (09/24/89)

In article <685@galen.acc.virginia.edu>, mlj8e@dale.acc.Virginia.EDU (Michael L. Johnson) writes:
>
>  Actually, didn't the extent file system come from SUN?
> 
> (804)-924-8607                   Michael L. Johnson
> mlj8e@virginia.EDU               Pharmacology Dept.
> uunet!virginia!mlj8e             Box 448; Univ. of Va.
> mlj8e@virginia.BITNET            Charlottesville, Va. 22908


Such statements as the preceding should not be made over a real return
address.  You are in danger of receiving a visit from Jack "The Knife", of
the Usenet Department of Permanent Corrections for Base Calumnies.

Sun had nothing to do with the Silicon Graphics EFS.  The file system Sun
pushed was NFS, Network File System.  Sun runs the Berkeley FFS, or Fast
File System, which as Kipp (who should know) says, is somewhat slower than
EFS.  Of course, anything is faster than the unspeakable, tiny-block-with-
jumbled-free-list SV BFS.


Vernon Schryver
Silicon Graphics
vjs@sgi.com

jmb@patton.sgi.com (Jim Barton) (09/25/89)

In article <685@galen.acc.virginia.edu>, mlj8e@dale.acc.Virginia.EDU (Michael L. Johnson) writes:
> In article <643@odin.SGI.COM> kipp@warp.sgi.com (Kipp Hickman) writes:
> >
> >The Extent File System is SGI's high performance filesystem running under
> >system V.  
> >					kipp hickman
> >					silicon graphics inc.
>  Actually, didn't the extent file system come from SUN?
>  
> 
> 
> (804)-924-8607                   Michael L. Johnson
> mlj8e@virginia.EDU               Pharmacology Dept.
> uunet!virginia!mlj8e             Box 448; Univ. of Va.
> mlj8e@virginia.BITNET            Charlottesville, Va. 22908

Aw, c'mon, don't insult us.  Sun hasn't invented a production filesystem
that I know of at anytime - they use the fairly standard BSD FFS code.
Mr. Hickman actually invented and wrote the code for the Extent File
System himself - I'm sure he would resent the slur.

-- Jim Barton
Silicon Graphics Computer Systems    "UNIX: Live Free Or Die!"
jmb@sgi.sgi.com, sgi!jmb@decwrl.dec.com, ...{decwrl,sun}!sgi!jmb

kipp@warp.sgi.com (Kipp Hickman) (09/25/89)

The extent filesystem was written by myself and Don Fong, an ex sgi
employee.  It has nothing whatsoever to do with SUN, except that it is
faster than the filesystem they use.

					kipp hickman
					silicon graphics inc.