Hi Eric. I am in the same boat and trying to determine a similar issue. I want to use ZEO because of what I can to to perform maintenance and testing without affecting production sites. I know it is not a problem to work with a mount point (separate database) for each virtual site in a single zope instance (but whether it is recommended to run a single zeo instance with multiple databases so each virtual site running under a ZEO client can still use its own zodb I would like to know more about). It is imperative for me to keep each clients' data in its own zodb for a variety of reasons (ie. backup, portability, scalability). I hope there are those with experience to comment on whether an approach like this is advised also. Dieter responded to my message yesterday about it being possible to run multiple zodb behind a single ZEO but whether or not it is recommended, I would like to know more about also. For me, the databases are small but nonetheless I want to keep them separate (and associated with each virtual site) regardless of whether they are being managed out of a single ZEO server or Zope instance. I would also like to keep this with a single ZEO if possible since a one to one ZEO server instance to zodb would not be so great on RAM resources of the server and in my opinion would be like using a cannon when you may only need a slingshot. Regards, David On Tuesday, September 20, 2005, at 03:36 PM, Eric Wohnlich wrote: I'm working on the scalability aspect of Zope, and am trying to see what the best practices are for creating multiple databases or multiple Zope instances. I am using ZEO and have allowed for multiple databases (Data.fs files) by editing zeo.conf just to try that out, because our current database is getting very large. The way I understand it, ZEO allows the work load to be distributed among multiple clients when you are getting a lot of hits, but does not address the issue of having a very large database for which it may slow down. So for this you would either create multiple instances of Zope/ZEO which each have their own database, or you would just create multiple databases within a single Zope/ZEO instance. Is there what is considered a best practice as far as choosing one of these options? Is there a database size I should try to maintain by distributing my Plone sites among different databases - or maybe just have a separate database for each? Or perhaps I am way off...   Eric _______________________________________________ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )