There are two cluster architecture approaches used at CERN to provide central CVS services. The first one (http://cern.ch/cvs) depends on AFS for central storage of repositories and offers automatic load-balancing and failover mechanisms. The second one (http://cern.ch/lcgcvs) is an N + 1 cluster based on local file systems, using data replication and not relying on AFS. It does not provide either dynamic load-balancing or automatic fail-over. Instead a series of tools were developed for

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... ory relocation in case of fail-over and for manual load-balancing. Both architectures are used in production at CERN and project managers can chose one or the other, depending on their needs. If eventually, one architecture proves to be significantly better, the other one may be phased out. This paper presents in detail both approaches and describes their relative advantages and drawbacks, as well as some data about them (number of repositories, average repository size, etc).