from lower to 2.3.x: database scheme has changed slightly -- MySQL: ALTER TABLE samhain.log ADD COLUMN acl_old BLOB; ALTER TABLE samhain.log ADD COLUMN acl_new BLOB; -- PostgreSQL: ALTER TABLE samhain.log ADD COLUMN acl_old TEXT; ALTER TABLE samhain.log ADD COLUMN acl_new TEXT; -- Oracle: ALTER TABLE samhain.log ADD acl_old VARCHAR2(4000); ALTER TABLE samhain.log ADD acl_new VARCHAR2(4000); DROP TRIGGER trigger_on_log; since 2.2.0: server-to-server relay is possible -- this implies that problems will arise if your server is misconfigured to connect to itself (SetExportSeverity is explicitely set to a threshold different from 'none', and the logserver is set to localhost). The server may deadlock in this case. since 2.1.0: update and daemon mode can be combined -- this implies that '-t update' will start a daemon process if running as daemon is the default specified in the config file. use '--foreground' to avoid starting a daemon process from 1.7.x to 1.8.x: client/server encryption protocol has been enhanced -- 1.7.x clients can connect to a 1.8.x server -- 1.8.x clients can only connect to a 1.7.x server, if they are built with --enable-encrypt=1 from 1.6.x to 1.7.x: things to watch out for -- the log server drops root privileges after startup; it needs a logfile directory with write access for the unprivileged user now -- the PID file does not double as lock for the log file anymore; the log file has its own lock now (same path, with .lock appended) -- by default, the HTML status page of the server is in the log directory now; this allows to make the data directory read-only for the server