diff --git a/doc/appendix-faq.sgml b/doc/appendix-faq.sgml index 8a79e872..c7dfc203 100644 --- a/doc/appendix-faq.sgml +++ b/doc/appendix-faq.sgml @@ -35,15 +35,25 @@ Replication slots, introduced in PostgreSQL 9.4, ensure that the primary server will retain WAL files until they have been consumed - by all standby servers. This makes WAL file management much easier, - and if used &repmgr; will no longer insist on a fixed minimum number - (default: 5000) of WAL files being retained. + by all standby servers. This means standby servers should never + fail due to not being able to retrieve required WAL files from the + primary. However this does mean that if a standby is no longer connected to the primary, the presence of the replication slot will cause WAL files - to be retained indefinitely. + to be retained indefinitely, and eventually lead to disk space + exhaustion. + + + + 2ndQuadrant's recommended configuration is to configure + Barman as a fallback + source of WAL files, rather than maintain replication slots for + each standby. See also: Using Barman as a WAL file source. + +