Hi. I am on E1.6.2 with Xen 3.4.3. I'm trying to understand the requirement to have two physical machines in order to get EBS working. I have one 'good' machine with numerous CPUs, lots of RAM, and lots of disk. I have one 'ok' machine with less of all of it, and the network between them is a slow 100Mb link.
I originally wanted to configure all of this on one box, and everything currently works except for EBS. So now I'm trying to figure out how to reconfigure things to get EBS working. Here are my questions:
1) What is the minimum component that can be split to a separate machine to get EBS working? Is it just the storage controller? I.E. can I leave everything else but SC on one machine or do I have to move CLC/CC/Walrus with the SC?
2) If #1 is true and I move just the SC to a separate machine, my EBS volumes would be physically stored on the 'ok' machine and exported over the network back to the 'good' machine, correct? I.E. whatever holds the SC also holds the EBS volumes. If so this presents a problem for me since the 'ok' machine has limited disk and a 100mb network which will make for poor IO back to the more powerful NC.
3) Can I move just CLC/CC/Walrus to the second machine, and leave the SC and NC on the same 'good' machine? This is probably ideal for me, since all disk IO would presumably be local on that machine which is where I have the most disk space and horsepower. The 'ok' machine probably can run the rest of it well.
I'm just trying to figure out what the options are to rearrange this on to two systems to get EBS working.
Thanks!
Hello,
the real restriction is NC co-located with the CC: not all network mode will work, so if you are not using SYSTEM mode you will want to have the NC on a different machines. All other services can stay on the same machine. To get EBS to work, you need to have the SC on a different machine then the NC (since aoe won't work in that case).
In your case I'd try to get all but the NC on the good machine, and put the NC on the ok machine. This will have the drawback of leaving a weaker machine as node. If you instead want to have the NC on the good machine, then you can put everything else on the ok machine and see how the performance are. Your option 3 won't work since SC and NC needs to be on different machines.
let us know how it goes and which kind of difference you see between your setups.
cheers
graziano