Raid with mdadm

[dsr at tao.merseine.nu (dsr at tao.merseine.nu)]

On Sat, Sep 13, 2003 at 01:57:24PM -0400, Doug Sweetser wrote:
> A side topic.  I realized that I could have made my RAID system with
> Reiser instead of ext3.  One potential advantage I heard about a
> Reiser files system is that it handles directories with many files in
> it better.  First, is that true?  Second, what number of files does
> that start to make a difference?  As always, feel free to ramble
> passionately on a tangent.

Yes and no and kind of and yes anyway.

The traditional Berkeley Filesystem, which is approximately the
inspiration for ext2, had a performance problem when the number of files
in a dir exceeded the capacity of a single inode to hold them. 

Ext2 had that problem at one time, I think, but it was improved. You
will still see workarounds intended to limit the number of files in a
directory, but these tend to be used by programs that handle many many
small files -- say, the hashing used by qmail to store the mail queue.

Reiser has advantages in handling small files and probably has an
overall advantage when handling many files of any kind, regardless of
directory distribution.

-dsr-

-- 
Network engineer / pre-sales engineer available in the Boston area.
http://tao.merseine.nu/~dsr