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From: orc@pell.chi.il.us (Orc)
Newsgroups: comp.unix.bsd.freebsd.misc,comp.os.linux.development.system
Subject: Re: The better (more suitable)Unix?? FreeBSD or Linux
Date: 17 Feb 1996 10:39:15 -0800
Organization: The Deacon Brodie Fan Club
Lines: 50
Message-ID: <4g57cj$gc3@pell.pell.chi.il.us>
References: <4er9hp$5ng@orb.direct.ca> <31220995.C4C54C1@acm.org> <4g0sam$r6p@agate.berkeley.edu> <4g33tp$esr@park.uvsc.edu>
NNTP-Posting-Host: pell.pell.chi.il.us
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:14566 comp.os.linux.development.system:18288
In article <4g33tp$esr@park.uvsc.edu>,
Terry Lambert <terry@lambert.org> wrote:
>nickkral@america.CS.Berkeley.EDU (Nick Kralevich) wrote:
>] In the extended abstract, they claim "On small file workloads, LInux is
>] order of magnitude faster [10 times] than the other systems [FreeBSD
>] and Solaris]". (items in brackets were added by me).
>
>From the same paper:
>
>"Given that we measured the average non-cached seek time of these
> systems to be 14ms (Figure 11), Linux is clearly not accessing
> the disk during this benchmark. This is because the Linux file
> system, ext2fs, uses and asynchronus metadata update policy,
> unlike the FreeBSD and Solaris file systems. While this gives
> Linux a performance advantage, it could result in losing more
> data after a system crash."
But alternatively, one might wonder what's the point of writing
the metadata unless you're also writing the data that the metadata
is pointing to. If the synchonous metadata writes that some
filesystem provide will happily put the filesystem information down
but then defer the data writes for a later date, that information
is completely useless and possibly harmful, and it doesn't make any
difference whether it's written out by religious mandate or by the
elevator passing by that floor.
>"FreeBSD writes files of less than eight megabytes 50% faster
> than Solaris or Linux. Linux maintains less than half the
> write bandwidth of FreeBSD or Solaris for almost all file sizes."
>
>[ ... more benchmarks ... ]
>
>The benchmarks described are against the 2.0 Alpha release. They
>are prior to the buffer cache unification. The Lai/Baker paper
>gives a better set of numbers.
Yes, and this is a known problem with Linux. Will it stay that way?
Dunno; certainly people are looking at the buffer caching and changes
may happen to it. But from my experience of relative performance (Linux
1.2 vs FreeBSD 2.0), this behavior is hidden by the default behavior of
the ext2 filesystem, which shows that it's hard to point at one behavior
of a system and say whether or not it's speeding things up or slowing it
down in regards to another system.
____
david parsons \bi/ orc@pell.com^H^Hhi.il.us
\/