Re: VMware and mirror/multimaster

[Michael Ströder <michael@stroeder.com>]

Howard Chu wrote:
> Howard Chu wrote:
> > Dave Horsfall wrote:
> > > Has anyone tried mirroring or multimaster under VMware i.e. are the
> > > virtual clocks stable enough?  We're starting to use VMware to cut 
> > > down on
> > > the number of physical hosts, but I'd like to use the latest 2.4 
> > > features
> > > as well.
> > I don't have any long-term experience with that setup, just use VMware 
> > for
> > short-duration tests. My suspicion is that the clock stability isn't very
> > good, and ntpd can't correct for it...
> Thinking about this some more - why would you ever do this?

1. Separation of operational processes at machine-level.
2. Importing, exporting, cloning, taking snapshots of VMs (e.g. I'm 
often preparing machines with VMWare workstation which are then imported 
into GSX/ESX server.)
3. HA with ESX cluster setups.
...

> If you're 
> consolidating many physical servers into a single physical server, just 
> run a single slapd on the consolidated server. You'll have more RAM 
> available and much less overhead.

Sometimes scaling up does not have the highest priority.

> If all of 
> your servers are going to just be in VMs running on the same machine, 
> and they're all replicating with each other, you have no hardware 
> redundancy, so you may as well just run a single slapd on the real machine.

One of my customers is running a VMWare ESX cluster in two separate 
datacenters. Very handy.

Ciao, Michael.