Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi Folks, I'm wondering if something is doable - comments please: I have a very specific situation where I'm trying to maintain a legacy high-availability application running in a Xen VM (Linux DomU). Current stack (per node, in a 2-node HA cluster): Applications VM (Linux DomU) --- auto failover to node 2 ---- DRBD ---- replicated to node 2 ---- LVM md raid Xen (Linux Dom0) We're looking at migrating our infrastructure to an OpenSolaris base (probably SmartOS), which will end up looking like this: VM (Linux KVM or Zone) ------------auto failover ot node 2 ----- <synchronous replication> ----- to node 2 ---- ZFS (exporting a ZVOL) KVM (or Zones) SmartOS The kicker, is that there is no available equivalent to DRBD for the illumos ecosystem - hence, my thought is to mount the ZVOL block device inside the 2 virtual machines, and use DRBD running on Linux inside the pair of VMs to achieve storage replication. Will DRBD run inside a virtual machine? Will it give any kind of reasonable performance? Are there any serious gotchas to watch out for? Three notes re. motivation and thinking: - for all our other applications, we're doing application layer replication (e.g., database sync) - but for smtp and list processing this doesn't seem easily doable (too many queues and messages in flight, asynchronously) - looking to move from Linux for a number of reasons, but particularly ZFS - looked at BSD, which has HAST as an equivalent of - virtualization is a mixed bag (Xen on NetBSD, but not FreeBSD; KVM sort of, a new hypervisor for FreeBSD), and ZFS is only stable on FreeBSD - can do some things on FreeBSD, some on NetBSD, but not all on the same one - and right now the illumos world seems to be gaining lot of momentum as the alternative open-source Unix Thanks very much, Miles Fidelman -- In theory, there is no difference between theory and practice. In practice, there is. .... Yogi Berra