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Date:      Mon, 15 Feb 1999 23:44:47 +0000
From:      Karl Pielorz <kpielorz@tdx.co.uk>
To:        Kent Stewart <kstewart@3-cities.com>
Cc:        Thomas van Gulick <melkor@Cal040031.student.utwente.nl>, freebsd-questions@FreeBSD.ORG
Subject:   Re: FreeBSD performance
Message-ID:  <36C8B16F.F3C5B7EE@tdx.co.uk>
References:  <19990215144708.A34665@utumno.student.utwente.nl> <36C83508.B7F45FC8@tdx.co.uk> <36C88049.A423185A@3-cities.com>

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Kent Stewart wrote:

> The argument of sync versus async on the writes only matter if you have a
> flaky system or are doing online database transactions.

Hmmm... Or if your dealing with directories with lots of files, lots of other
directories, writes to lots of files in those directories - or you have reason
to use the 'rm -rf *' liberally :-)

> The delay for the
> writes are only a couple of seconds. That is why you used to "sync" disks at
> shutdown.

Sorry, I don't quite follow this... Although I'm not too up on FreeBSD's sync
mounts, I know that softupdates 'delays' can run to around 30 seconds or so,
I'm fairly sure 'sync' mounts delays under FreeBSD are similar (i.e. more than
a couple of seconds delay, especially under load where it has to play
'catchup'?) - and you _still_ need to 'sync' before you shutdown these days
:-)

I think in order of preference I would take softupdates, async and then
sync... The original complaint was of general FreeBSD 'sluggishness' - though
I suspect some of this might be the filesystem differences between 'in vogue'
versions of Linux and stock 2.2.X relelases of FreeBSD - going on that's what
I first noticed when I made the switch (apart from an increase in throughput,
a decrease in load average and a hell of a lot more stability when under
pressure).

I can't see it making all the difference in this case (yet)...

I guess we'll have to wait for the original poster to post again...

In the meantime this thread is getting a little out-of-step for -questions,
though I'm open to suggestions on where to take it <G>

-Kp

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