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Date:      Mon, 27 Jan 1997 21:08:56 +1100
From:      Bruce Evans <bde@zeta.org.au>
To:        dicen@hooked.net, freebsd-hackers@FreeBSD.ORG
Subject:   Re: Performance of ufs vs. ext2.
Message-ID:  <199701271008.VAA00439@godzilla.zeta.org.au>

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>Okay cool some real numbers. When you speak of "rewrite" are you talking
>about the creation and deletion of files (Metadata)? There seams to be a

It's whatever the bonnie benchmark does.  Something like rewriting the
data in an existing file using a too-small blocksize.  The small blocksize
forces blocks to be written to be pre-read unless the OS is very smart.
It is normally at least twice as slow as an append with a too-small
blocksize because it involves twice as much i/o.  Under FreeBSD it is
about 3 times as slow.  Under Linux it is only twice as slow.

>significant speed difference between the creation and deletion of files
>on linux ext2 vs. Freebsd ufs. Linux ext2 is way faster. I suppose I

This is caused mainly by a different default for synchronization of writes:
FreeBSD: mount -o -noasync: usually safer but always slower.
Linux: mount -o -async: usually less safe but always faster.

>could just run ext2 under FreeBSD right? It sure would make a "make
>world" faster. You know if someone were to setup a news server it would
>seam to make more sence to use ext2.

No, the file system has very little to do with the speed of create/delete.
FreeBSD uses the same mount default for ext2fs and ufs.  `mount -o async'
speeds them up almost equally so that they are both slightly slower for
create/delete than Linux.  They are slower because Linux has better
support for its default setting.

Bruce



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