Further for the records (for a future upgrade to newer ZK versions):
There will likely need to be a NEWS.Debian entry about the following: https://issues.apache.org/jira/browse/ZOOKEEPER-3056 In short: - apparently they've added a check that prevents ZK from starting, when no snapshots were found in the dataDir - the workaround is to ONCE set snapshot.trust.empty=true (the zookeeper.snapshot.trust.empty=true mentioned in most messages of the bug does not work, which is mentioned in some later answers) - start up the server - remove the setting again quoting: "It is recommended to remove the property once you have a working server, because that check is important to ensure that the system is in good shape" Cheers, Chris.