Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi Miles, Yes - I run DRBD inside KVM virtual machines in production just fine. There were no performance issues or real gotchas that I've encountered. I was just careful to not base the VM's storage on DRBD *outside* the VM in case I accidentally had both VMs running on the same physical server ;) I was also careful to maintain separate front and back networks by bridging two separate virtual NICs in the VM to two separate physical NICs on two separate networks on the physical host just as I do with DRBD on "real" servers. HTH, Simon. On 23/07/14 23:23, Miles Fidelman wrote: > 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 > > > > > >