related to the Citrix-vs-VMware question, in the spirit of the times... I want to create a way to host a cheap HA solution for a web hosting outfit. they are running a few pretty busy asymetric servers and want to start improving that infrastructure. each machine holds several dozens of virtual hosts.
At the moment each server has its own local storage and mysql. every part is a SPOF other than the minimal RAID and such things. I'm thinking: * Move to a central non-virtual MySQL for the backend. * have two servers go P2V and have those VMs hosted back on their original hardwares (sadly this means some painful downtime), and find a way to let them crash-migrate for HA (still trying to figure this out) * Second stage, add a second MySQL in a master-master setup. I'd love to have two servers with symetrical setup, but as you can guess, the virtual hots are dozens of different apps that are too expensive to go and rewrite for clusters at this point, with the issues of user-uploaded files having to be available to both Apaches, etc. Assuming we want the cheapest reliable solution, i.e. not a $6K-20K SAN and FC, I am looking for an easier solution (easier on the pocket at least). However NFS proved to be a disaster in such cases (high-load web services), OCFS has not been nice to me with any setup other than maybe Oracle clusters, and GFS also never ran smoothly in my tests. Also OCFS and GFS require a common disk, which at this budget would be a Linux machine running an iSCSI target at best (or OpenNAS). Am I missing something? Can this kind of reliability be achieved without shelling out big bucks? Of course, The other option is just separate the MySQL, have a third machine rsync the files of the two (non virtual) servers every few minutes and have the hosting farm's layer4 switch redirect to the fallback if something happens. Not very "smart" nor scalable, but does 70% of what we need till a bigger investment is required. your thoughts, as before, are welcome... Thanks, Ira. -- Can't catch me yet Ira Abramov http://ira.abramov.org/email/ _______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il