On Wed, Apr 18, 2012 at 09:54:58PM +0200, Gandalf Corvotempesta wrote: > we are planning a new infrastructure based on gluster to be used by > some mail servers and some web servers. > > We plan 4 server, with 6x 2TB SATA disks in RAID-5 hardware each. > > In a replicate-distribute volume we will have 20TB of available space. > > What do you suggest, a single XFS volume and then split webstorage and > mailstorage by directory or do you suggest to create two different > mount points with different replicate-distribute volume? > > any performance degradation making 2 or more volumes instead a single > one? Much less than the performance degradation you'll get from using RAID-5! If you use 6 x 3TB disks in RAID10 you'll have almost the same amount of storage space, but far better performance, at almost the same price. I'd say this is very important for a mail server where you are constantly writing and deleting small files. RAID10 with a large stripe size should localise file I/O from one user to one disk (read) or two disks (write), so that there is spare seek capacity on the other 4 disks for concurrent accesses from other users. As for partitioning: note that you can create separate bricks on the same disk. e.g. if the RAID arrays are mounted on server1:/data, server2:/data etc then you can create your web volume out of server1:/data/web server2:/data/web ...etc and your mail volume out of server1:/data/mail server2:/data/mail ...etc This doesn't gain you any performance, but gives you a little more flexibility and manageability (e.g. you can more easily look at I/O usage patterns separately for the two volumes, or migrate your web volume onto other bricks without moving your mail volume) Regards, Brian.
