heavy NFS writes lead to corrup summary in superblock
Eric Anderson
anderson at centtech.com
Fri Jun 9 12:27:55 UTC 2006
Oliver Fromme wrote:
> Mikhail Teterin <mi+mx at aldan.algebra.com> wrote:
> > The FS is intended for very few very large files and was created
> > with "newfs -b 65536 -O1" (no softupdates).
>
> Did you also increase the fragment size (-f option)?
> The default is 2048 bytes, and I wouldn't expect a b/f
> ratio of 32:1 to work very well. In fact I'm surprised
> that you have so little problems. :-)
>
> If you intend to have very few very large files that are
> accessed sequentially most of the time, it is probably
> better to set both block and fragment size to the same
> value (e.g. 16k), essentially disabling fragmentation.
> You should also reduce the inode density by specifying
> a larger bytes-per-inode value (-i option), a typical
> value would be 262144 (2^18).
>
> Carefully fiddling with the -g and -h options might also
> improve performance a bit, see newfs(8).
He should also use UFS2, and disable softupdates (if he really doesn't
want them). No reason I can think of to use UFS1, but that doesn't mean
there isn't a bug lurking in UFS1.
Eric
--
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Eric Anderson Sr. Systems Administrator Centaur Technology
Anything that works is better than anything that doesn't.
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