3 ms·

Are your target boxes virtual machines? I always prefer the strategy where mirroring the data happens before the disk is presented to the VM. Have a look at G

• lsc 17y ago
  Virtual private servers, yes. I use Xen. And I agree, giving the user 2 block devices and expecting them to mirror is a very bad idea. I know this from experience. in an earlier setup, I'd give each user two block devices, one from each disk in the box. the idea being the user would mirror or not as appropriate. well, you loose a customers data, you loose the customer. Lesson learned. But this is where my virtual setup gives me an edge. On every Xen server, I have a control guest or driver domain, the dom0. all disk and net I/O goes through the dom0 anyhow, so there wouldn't be much more overhead to me doing the mirroring on the Dom0, and passing the md through to the DomU (what the user controls.) I'm not adding another point of failure, either; if the dom0 chokes, all guests on the system will crash regardless.