Quote:
Originally Posted by
DukeNuke2
imho this is no knowledge to serach in a forum. this is mission critical and should be done by specialised consultants!
hehe, yeah, when it comes to the implementation phase i'll probably be hitting up Sun for more assistance. at this point i'm trying to find out what others are doing out there to see if has been done before. my preference is to drop the whole virtualization idea entirely and just cluster applications with virtual IPs. i'm willing to give zones (and even LDOMs for that matter) a chance, but so far i don't think either one will give us the availability that we're looking for. basically i want an HA environment that meets the following needs:
1 - can handle hardware failures
2 - can handle OS issues such as panics
3 - needs minimal downtime for system maintenance
4 - provide ability to store application logs all together
5 - can dynamically expand filesystems or add storage to a live system.
so, 1 is straight forward and can be handled by a normal app cluster, clustered zones and clustered ldoms.
2 is straight forward and can be handled by app cluster and clustered zones in a particular configuration. ldoms have the issue that if anything happens to that OS, the app will be down until it can be repaired or restored.
3 can be handled by an app cluster and with clustered zones in a particular config. ldoms can't do this because you have one OS that you are stuck with through failures, patches, etc.
4. app cluster works with this again. if we configure zone cluster so that 2 and 3 are met, then this one can't be without some sort of shared storage option (say NFS or some sort of clustered filesystem). ldoms are fine with this because everything is stuck together anyway, app, os and everything.
5. app cluster is fine with this. ldoms completely fail at this because you need a reboot to modify filesystems or storage. i'm not sure about zones. since zones just remap local filesystems, will they recognize if a filesystem has grown?
By the way, the particular configuration that I mentioned for zones is that you have your zones local instead of on shared storage that you fail over. This is what Symantec recommends for clustered zones. So, you have zone A on server 1 with some hostname. Then you have zone B on server 2 with the same hostname. Then, you just start up the IP on whichever zone you want your end users/clients to connect to. Now you have two separate environments that you maintain which allows for patching of the offline zone while the other one is still servicing clients. The only problem I have then is that I can't seem to find a nice way to migrate the application data between these two zones with the IP and we can't have application logs spread between two zones.