On Wed, 2008-09-10 at 15:00 -0400, Maurice Volaski wrote: > >On Wed, 2008-09-10 at 14:36 -0400, Maurice Volaski wrote: > >> A disadvantage, however, is that Sun StorageTek Availability Suite > >> (AVS), the DRBD equivalent in OpenSolaris, is much less flexible than > >> DRBD. For example, AVS is intended to replicate in one direction, > >> from a primary to a secondary, whereas DRBD can switch on the fly. > >> See > >> http://www.opensolaris.org/jive/thread.jspa?threadID=68881&tstart=30 > >> for details on this. > > > >I would be curious to see production environments "switching" direction > >on the fly at that low level... Usually some top-level brain does that > >in context of HA fail-over and so on. > > By switching on the fly, I mean if the primary services are taken > down and then brought up on the secondary, the direction of > synchronization gets reversed. That's not possible with AVS because... > > >well, AVS actually does reverse synchronization and does it very good. > > It's a one-time operation that "re-reverses" once it completes.
When primary is repaired you want to have it on-line and retain the changes made on the secondary. Your secondary did the job and switched back to its secondary role. This HA fail-back cycle could be repeated as many times as you need using reverse sync command. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
