improving concurrency/performance

[David Lang]

On Mon, 7 Nov 2005, Jure Pe?ar wrote:

> On Sun, 6 Nov 2005 14:20:03 -0800 (PST)
> Andrew Morgan <morgan at orst.edu> wrote:
>
>> mkfs -t ext3 -j -m 1 -O dir_index /dev/sdb1
>> tune2fs -c 0 -i 0 /dev/sdb1
>
> What about 1k blocks? I think they'd be more useful than 4k on mail
> spools ...

I was recently doing some testing of lots of small files on the various 
filesystems, and I ran into a huge difference (8x) depending on what 
allocator was used for ext*. the default allocator changed between ext2 
and ext3 (you can override it as a mount option) and when reading 1M files 
(10 dirs of 10 dirs of 10 dirs of 1000 1K files) the time to read them 
went from ~5 min with the old allocator useed in ext2 to 40 min for the 
one that's the default for ext3.

David Lang

-- 
There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies.
  -- C.A.R. Hoare