[Gluster-users] my own unify - raid5 setup, is it possible?

[Casper Langemeijer]

Hi all,

I've been toying around with glusterfs 2.0.9 and I'm really liking it. I
very much enjoy it's simple modular design.

My current test setup is a unify cluster, using a afr/loadbalanced
namespace.

Could I duplicate files to multiple data bricks in the cluster to
provide a raid5-like setup? I very much want to be able to shutdown a
single machine in the cluster and still have a fully functional
filesystem. I'm very happy to write the application that does the
copying over the data bricks myself.

Another advantage could be that I can decide on a per-file basis how
many copies of a file exist in the filesystem. (Two would be a minimum
for me) The real-world scenario: This would be the data filesystem for a
webserver cluster setup. You can imagine images used on a homepage are
requested more frequent than others.

I imagine the order in which I specify the subvolumes in the unify
volume needs to be different over my clients to make good use of the
multiple copies over the different bricks.

What problems can I expect with this setup?
Have others tried a similar setup?
Am I missing a GlusterFS feature that would implement what I want, in a
much easier way?

Thank you for your time!

Some other minor remarks:

* Is there a reason the AFR translator is missing in the wiki on:
http://gluster.com/community/documentation/index.php/Translators ?

* The wiki search does not work for small words (AFR for example) This
is because MySQL full text search indexes are used, and mysql has a
minimum char length. Add 'ft_min_word_len=2' to the mysql my.cnf file
(in the mysqld section) To create indexes of 2 and 3 letter words too.
This results in larger indexes, but I think it's worth it.