Working on documentation.

INSTALL.md

@@ -4,6 +4,57 @@
 
 ## configuration
 
+BackRest takes some command-line parameters, but depends on a configuration file for most of the settings.  The default location for the configuration file is /etc/pg_backrest.conf.
+
+### configuration sections
+
+Each section defines important aspects of the backup.
+
+#### command section
+
+The command section defines external commands that are used by BackRest.
+
+##### psql key
+
+Defines the full path to psql.  psql is used to call pg_start_backup() and pg_stop_backup().  Example:
+
+psql=/usr/bin/psql
+
+##### remote key
+
+Defines the file path to pg\_backrest\_remote.pl.  
+
+
+    CONFIG_SECTION_COMMAND        => "command",
+    CONFIG_SECTION_COMMAND_OPTION => "command:option",
+    CONFIG_SECTION_LOG            => "log",
+    CONFIG_SECTION_BACKUP         => "backup",
+    CONFIG_SECTION_ARCHIVE        => "archive",
+    CONFIG_SECTION_RETENTION      => "retention",
+    CONFIG_SECTION_STANZA         => "stanza",
+
+    CONFIG_KEY_USER               => "user",
+    CONFIG_KEY_HOST               => "host",
+    CONFIG_KEY_PATH               => "path",
+
+    CONFIG_KEY_THREAD_MAX         => "thread-max",
+    CONFIG_KEY_THREAD_TIMEOUT     => "thread-timeout",
+    CONFIG_KEY_HARDLINK           => "hardlink",
+    CONFIG_KEY_ARCHIVE_REQUIRED   => "archive-required",
+    CONFIG_KEY_ARCHIVE_MAX_MB     => "archive-max-mb",
+    CONFIG_KEY_START_FAST         => "start_fast",
+    CONFIG_KEY_COMPRESS_ASYNC     => "compress-async",
+
+    CONFIG_KEY_LEVEL_FILE         => "level-file",
+    CONFIG_KEY_LEVEL_CONSOLE      => "level-console",
+
+    CONFIG_KEY_COMPRESS           => "compress",
+    CONFIG_KEY_CHECKSUM           => "checksum",
+    CONFIG_KEY_PSQL               => "psql",
+    CONFIG_KEY_REMOTE             => "remote"
+
+### configuration examples
+
 ## sample ubuntu 12.04 install
 
 apt-get update