OK, how feasible is it to rent some commodity servers from the likes of a cheapo host like 1and1 and turn them into something robust?
Right now I have had some success taking a rented box and using vservers to run multiple virtual machines. It's then easy to add new physical servers and shunt services around. However, we had the hardware lockup on one machine recently and suddenly everything on that machine becomes unavailable... So now I'm trying to figure out how to make this system robust against hardware failure as well. Apps are a mailserver (Dovecot+Postfix) and a custom Rails webapp (currently under Apache, but considering alternatives). Clearly it's a piece of cake to build two identical mail/webservers, the bits I am not quite understanding are: 1) How to load balance to my hypothetical backend of 3 (or so) identical machines? (remember I am using some rented boxes so I can't shift IP addresses around and have just 100mbit ethernet between everything) 2) How to create reliable persistant storage for the mail and webservers? Assuming only the rented boxes described (as many as you like!), is it possible to do better than simply playing DNS tricks to keep availability if backend machines go down? (ie solve (1) above). Seems like I can either use simple dns round robin to the backend servers if thats all I need, or I can fit two loadbalancer machines (or some description) in front if I need better balancing - however, one way or another I'm back to the situation that the loadbalancer hardware could go bad? There is conflicting advice on best practice to solve 2) above. Given only a single net connection to each of the machines, split brain type problems seem like a normal situation? However, this particular host provides a net based serial console and also a net based method to forceably reboot the machine (or take it down), however the later is not instant and may take some fiddling to automate usage of these features. Also the limitation is still that net interface... What happens when someone blows up an internal router and the network becomes subtly internally broken? What would be best for this situation to run reliable mysql + mail storage + webserver storage? Gluster? DRBD + OCFS ?? Something else? (Pay through the nose for a san...?) Grateful for some pointers to get started here? Ed W _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
