On Tue, Jul 15, 2008 at 5:25 PM, Martin Fick <mogulguy@yahoo.com> wrote: > --- On Tue, 7/15/08, Edward Capriolo <edlinuxguru@gmail.com> wrote: > >> > >> I have setup glusterfs between vservers. It seems to work >> well under very limited testing. I do not understand why you would >> need to run gluster ontop of DRBD, but you probably can prove me >> wrong. I am sure there are good reasons to :) > > Simple, glusterfs AFR does not prevent split brain operation. AFR is well suited for clusters where nodes rarely go down and can be expected to come back up before any others go down and where network outages are very unlikely. Glusterfs AFR really is a very simplistic node replication algorithm that is meant more for providing high availability but it does not yet ensure consistent data. If you have lots of disks and can do AFR with several copies (more than 2) than it might be safer, but that might also kill you performance. Search or ask on the glusterfs mailing list if you want to know more why AFR might not be a good idea for this. > > -Martin > > > > > Hey don't sigh over java. I notice that usually people will run any type of interpreted or scripting language but you say JAVA and they are like 'Java No Way!'. It is a debate for another place but I always say 'Don't knock it until you tried it'. As it applies to this circumstance, with Hadoop and JAVA I was able to get a running solution up in about 2 hours after I followed a simple tutorial. It took A LOT of digging to get gluster working, probably about 3 days of research on my part poking around in IRC rooms Luster,Openvz,vserver, piecing cryptic mailserver posts together. It took me two days of research before I figured out LUSTER was just not going to work with vserver. I had a nightmare experience or two with DRBD. For kicks 'google linux-ha, drbd' and my email to see me trying to setup a two node DRBD cluster and running into every problem but the kitchen sink, disk formatting, kernel updates, lockups. You can not compare the three. HADOOP is not a general purpose filesystem, more like filesystem+grid computing. Yahoo is using it and apache foundation is developing it, so like before you pass it up think on that. GlusterFS seems really impressive. I wish I had more time for it. Seems like you can do just about anything with it. Network mirrors/ network stripes/ file replication. I never benchmarked it. Once I figured out the install it seems to be pretty easy. DRBD has its place as a more ACTIVE/PASSIVE ACTIVE/ACTIVE fail over solution with very low level replication. It is not going to scale past three servers.