*BSD News Article 62479


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Newsgroups: comp.unix.bsd.freebsd.misc,comp.os.linux.development.system
Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nntp.coast.net!torn!howland.reston.ans.net!EU.net!sun4nl!rnzll3!sys3.pe1chl!rob
From: rob@pe1chl.ampr.org (Rob Janssen)
Subject: Re: The better (more suitable)Unix?? FreeBSD or Linux
Reply-To: pe1chl@wab-tis.rabobank.nl
Organization: PE1CHL
Message-ID: <DMzqnM.DnK@pe1chl.ampr.org>
References: <4er9hp$5ng@orb.direct.ca> <4fg8fe$j9i@pell.pell.chi.il.us> <311C5EB4.2F1CF0FB@freebsd.org> <4fjodg$o8k@venger.snds.com> <4fo1tu$n31@news.jf.intel.com> <DMrCE4.3HF@pe1chl.ampr.org> <4ftjt9$fjs@park.uvsc.edu> <DMv8w7.8H4@pe1chl.ampr.org> <4g5ivp$28m@park.uvsc.edu>
Date: Sun, 18 Feb 1996 21:35:45 GMT
Lines: 52
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:14612 comp.os.linux.development.system:18341

In <4g5ivp$28m@park.uvsc.edu> Terry Lambert <terry@lambert.org> writes:

>rob@pe1chl.ampr.org (Rob Janssen) wrote:
>] So, what is it that synchronously updating metadata is really buying you?
>] 
>] When the answer is "nothing, really" and it does slowdown the system,
>] I don's see why I would use it.
>] When you want to use it, go ahead.

>Sigh.

>I know my explanations have been more technical than the average
>user's interest level.  I will try and distill them:


>1)	Sync enhances the security of your files following a
>	crash and makes sure that part of one of your files
>	does not end up in someone elses hands.

There is no proof that this will happen with ext2fs, and it is
not likely that it will.

>2)	Sync increases the probability that things you did
>	right before the machine went down on you aren't going
>	to get lost.

This is just plain wrong, unless both data and metadata are written sync.

>3)	Sync makes your machine go slower on a bogus-as-hell
>	create 1000 files/delete 1000 files benchmark that
>	really doesn't mimic normal system usage at all.

Except when the machine is used as a news server, or when packages
are being installed on it.

>4)	Sync makes no difference in user perception of speed
>	unless you're the type of user who lives to run bogus
>	benchmarks, and then claim they represent a single
>	figure-of-merit to use when picking your machine.

I'm very sure that the abysmal performance of news expiry and unbatching
on the machine I discussed before is due to the sync metadata writes.
You call that a bogus benchmark.

As I said before, when you want to use it, go ahead.  I won't.

Rob
-- 
+------------------------------------+--------------------------------------+
| Rob Janssen         rob@knoware.nl | BBS: +31-302870036 (2300-0730 local) |
| AMPRnet:       rob@pe1chl.ampr.org | AX.25 BBS: PE1CHL@PI8WNO.#UTR.NLD.EU |
+------------------------------------+--------------------------------------+