File system performance

[David Dawes]

>From article <294 at audfax.audiofax.com>, by arnold at audiofax.com (Arnold Robbins):
> rcd at ico.isc.com (Dick Dunn) writes:
>>  The BSD-style file system is a far better performer.
> 
> In article <1990Nov01.114726.14348 at nstar.uucp> larry at nstar.uucp (Larry Snyder) writes:
>>Yes - but 8K blocks - just think what that would do to your partition
>>with all the news articles --
> 
> The BSD file system has both blocks and fragments.  On an 8K file system
> the fragment size will be 1K; files that are less than that in size only
> take up a single 1K fragment.  This is even more efficient than the 2K
> file system which uses 2K blocks.  So, go right ahead and put your news
> partition on BSD file system'ed partition.
> 
> I have to testify as to the speed of the BSD filesystem.  When we switched
> to it with ESIX rev D our systems sped up very noticeably!

I too am using ESIX rev D with ffs.  One of my file systems became heavily
fragmented, and got to the point where there were 0 free blocks, and
5000 free frags.  df reported 10000 blocks free, but attempting to write
to the file system resulted in "Disk full" errors.  This meant that I
had an unusable 5MB on a 65MB file system. (BTW, there were plenty of free
inodes.)

Is this how FFS is supposed to work, or is there a problem with the ESIX
implementation?

David
--
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 David Dawes (dawes at suphys.physics.su.oz.au) DoD#210   | Phone: +612 692 2639
 School of Physics, University of Sydney, Australia    | Fax:   +612 660 2903
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