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Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 863ac31c6b4..ee4925d6d92 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -9721,6 +9721,41 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' </listitem> </varlistentry> + <varlistentry id="guc-recovery-init-sync-method" xreflabel="recovery_init_sync_method"> + <term><varname>recovery_init_sync_method</varname> (<type>enum</type>) + <indexterm> + <primary><varname>recovery_init_sync_method</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + When set to <literal>fsync</literal>, which is the default, + <productname>PostgreSQL</productname> will recursively open and + synchronize all files in the data directory before crash recovery + begins. The search for files will follow symbolic links for the WAL + directory and each configured tablespace (but not any other symbolic + links). This is intended to make sure that all WAL and data files are + durably stored on disk before replaying changes. This applies whenever + starting a database cluster that did not shut down cleanly, including + copies created with <application>pg_basebackup</application>. + </para> + <para> + On Linux, <literal>syncfs</literal> may be used instead, to ask the + operating system to synchronize the whole file systems that contain the + data directory, the WAL files and each tablespace (but not any other + file systems that may be reachable through symbolic links). This may + be a lot faster than the <literal>fsync</literal> setting, because it + doesn't need to open each file one by one. On the other hand, it may + be slower if a file system is shared by other applications that + modify a lot of files, since those files will also be written to disk. + Furthermore, on versions of Linux before 5.8, I/O errors encountered + while writing data to disk may not be reported to + <productname>PostgreSQL</productname>, and relevant error messages may + appear only in kernel logs. + </para> + </listitem> + </varlistentry> + </variablelist> </sect1> |