[Gluster-users] GlusterFS and automated balancing

[Eros Candelaresi]

Hi,

for my small webhosting (3 servers, more to come hopefully) I am 
investigating cluster filesystems. I have seen a few now and I love the 
flexibility that GlusterFS brings. Still I cannot see a way to adapt it 
to suit my needs. I have the following hardware:
- Server #1 with 160GB S-ATA
- Server #2 with 2x 400GB S-ATA
- Server #3 with 2x 1,5TB S-ATA

I am hoping to find a filesystem that fulfills the following requirements:
1. POSIX compliant (Apache, Postfix, etc. will use it) - GlusterFS has it
2. combine the harddisks of all servers into one single filesystem - 
DHT/unify seem to do the job
3. redundancy: have a copy of each single file on at least 2 machines 
such that a single host may fail without people noticing - looks like 
this may be achieved by having AFR below DHT/Unify
4. after a server failure redundancy should automatically be recreated 
(ie. create new copies of all files that only exist once after the crash)
5. just throw in new hardware, connect it with the cluster and let the 
filesystem take care of filling it with data

Hadoop seems strong on points 2.-5. but fails in 1. and is unsuited for 
small files. For GlusterFS however, I cannot see how to achieve 4.-5. 
There always seems to be manual reconfiguration and data movement 
involved, is this correct? Since most of the Wiki is still based on 2.0 
and there is 3.0 out now, I may be missing something.

Hoping for your comments.

Thanks and regards,
Eros