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From: Terry Lambert <terry@cs.weber.edu>
Newsgroups: comp.os.386bsd.development
Subject: Re: DoubleSpace for UFS?
Date: 18 Feb 1995 22:16:30 GMT
Organization: Utah Valley State College, Orem, Utah
Lines: 37
Message-ID: <3i5rju$drn@park.uvsc.edu>
References: <D47HrE.CK7@murdoch.acc.Virginia.EDU>
NNTP-Posting-Host: hecate.artisoft.com
act9m@mamba.cs.Virginia.EDU (Alan Chih-Chang Tai) wrote:
] As a class project, my team is considering implemeting an on-the-fly
] disk compression for the Unix File System. My questions are:
] 1) how feasible is this?
Very (see #2)
] 2) has this been done before?
Yes. Check out the Ficus filesystem papers on ftp.cs.ucla.edu.
The current BSD FS code is based on this work. One class project
was a compressing FS.
There is also a commercial compressing UFS for UnixWare and other
commercial SVR4 UNIX implementations (they advertise in the trade
rags).
There is a PD implementation that is a user space NFS server for
loopback local mount (like AMD and hlfsd, etc.). I can't remember
the name, but it was on wuarchive, gatekeeper, and uunet the last
time I went looking.
Note also that there is kernel support in the curent FreeBSD snaps
for autogunzip on reference for loading binaries (this was flying
around on the hackers mailing list recently).
] 3) would this involve mucking around with the kernel?
Yes. Unless you went the user space route (at a significant penalty
to performance).
Terry Lambert
terry@cs.weber.edu
---
Any opinions in this posting are my own and not those of my present
or previous employers.