Messages in this thread | | | Date | Mon, 18 Feb 2008 16:18:23 +0100 | From | Andi Kleen <> | Subject | Re: very poor ext3 write performance on big filesystems? |
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On Mon, Feb 18, 2008 at 09:16:41AM -0500, Theodore Tso wrote: > ext3 tries to keep inodes in the same block group as their containing > directory. If you have lots of hard links, obviously it can't really > do that, especially since we don't have a good way at mkdir time to > tell the filesystem, "Psst! This is going to be a hard link clone of > that directory over there, put it in the same block group".
Hmm, you think such a hint interface would be worth it?
> > > What has helped a bit was to recreate the file system with -O^dir_index > > dir_index seems to cause more seeks. > > Part of it may have simply been recreating the filesystem, not
Undoubtedly.
> necessarily removing the dir_index feature. Dir_index speeds up > individual lookups, but it slows down workloads that do a readdir
But only for large directories right? For kernel source like directory sizes it seems to be a general loss.
-Andi
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