glenn@suphys.physics.su.OZ.AU (Glenn Geers) (05/02/91)
Hi, I'm using ESIX rev. D with only fast filesystems. I've cut back NBUFS to 100 (despite the 200 min. in /etc/conf/cf.d/mtune - I changed the min. to 100) and increased the number of ffs buffers to 128 (I have 300 Mb on line - two filesystems are 8192/1024 (sys V directory structure) and the other is 4096/1024 (BSD directory structure)). Performance does not appear to have suffered. Is there any advantage in increasing the number of ffsbufs? When the system pages from the file system is the buffer cache bypassed (on BSD it is. Bach - The Design of The Unix System - doesn`t say or I might have missed it)? If the cache is not bypassed which cache is used - the ffs one or the standard one? Thanks in advance, Glenn -- ___________________________________________________________________________ Glenn Geers | "So when it's over, | we're back to people. Department of Theoretical Physics | Just to prove that human touch The University of Sydney | can have no equal." Sydney NSW 2006 Australia | - Basia Trzetrzelewska, 'Prime Time TV' | Phone: +61 2 692-3241 (voice) |_________________________________________ +61 2 660-2903 (fax) | | glenn@qed.physics.su.oz.au | #include <standard_disclaimer.h> | ----------------------------------------------------------------------------
john@jwt.UUCP (John Temples) (05/03/91)
In article <1991May1.230130.29527@metro.ucc.su.OZ.AU> glenn@suphys.physics.su.OZ.AU (Glenn Geers) writes: >I'm using ESIX rev. D with only fast filesystems. I've cut back NBUFS >to 100 and increased the number of ffs buffers to 128. >Is there any advantage in increasing the number of ffsbufs? My understanding from talking to tech support is that NBUF allocates S51K cache buffers, which are not used if you've only got FFS file systems. FFSBUFFERS determines the cache size for the FFS (at 8K bytes per buffer). My system happens to be configured identically to yours, and I'm very pleased with my disk performance. -- John W. Temples -- john@jwt.UUCP (uunet!jwt!john)