pct: include information about pct restore

diff --git a/pct.adoc b/pct.adoc
index 40028b70f4b0796933ad342cc2bf186a7cd5aba5..51b15cc71da1d6b1919c54979ab3a416467e3a44 100644 (file)
--- a/pct.adoc
+++ b/pct.adoc
@@ -458,9 +458,64 @@ include::pct-network-opts.adoc[]
 Backup and Restore
 ------------------
 
 Backup and Restore
 ------------------
 

+Container Backup
+~~~~~~~~~~~~~~~~
+

 It is possible to use the 'vzdump' tool for container backup. Please
 refer to the 'vzdump' manual page for details.
 
 It is possible to use the 'vzdump' tool for container backup. Please
 refer to the 'vzdump' manual page for details.
 

+Restoring Container Backups
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Restoring container backups made with 'vzdump' is possible using the
+'pct restore' command. By default, 'pct restore' will attempt to restore as much
+of the backed up container configuration as possible. It is possible to override
+the backed up configuration by manually setting container options on the command
+line (see the 'pct' manual page for details).
+
+NOTE: 'pvesm extractconfig' can be used to view the backed up configuration
+contained in a vzdump archive.
+
+There are two basic restore modes, only differing by their handling of mount
+points:
+
+."Simple" restore mode
+
+If neither the `rootfs` parameter nor any of the optional `mpX` parameters
+are explicitly set, the mount point configuration from the backed up
+configuration file is restored using the following steps:
+
+. Extract mount points and their options from backup
+. Create volumes for storage backed mount points (on storage provided with the
+`storage` parameter, or default local storage if unset)
+. Extract files from backup archive
+. Add bind and device mount points to restored configuration (limited to root user)
+
+NOTE: Since bind and device mount points are never backed up, no files are
+restored in the last step, but only the configuration options. The assumption
+is that such mount points are either backed up with another mechanism (e.g.,
+NFS space that is bind mounted into many containers), or not intended to be
+backed up at all.
+
+This simple mode is also used by the container restore operations in the web
+interface.
+
+."Advanced" restore mode
+
+By setting the `rootfs` parameter (and optionally, any combination of `mpX`
+parameters), the 'pct restore' command is automatically switched into an
+advanced mode. This advanced mode completely ignores the `rootfs` and `mpX`
+configuration options contained in the backup archive, and instead only
+uses the options explicitly provided as parameters.
+
+This mode allows flexible configuration of mount point settings at restore time,
+for example:
+
+* Set target storages, volume sizes and other options for each mount point
+individually
+* Redistribute backed up files according to new mount point scheme
+* Restore to device and/or bind mount points (limited to root user)
+

 
 Managing Containers with 'pct'
 ------------------------------
 
 Managing Containers with 'pct'
 ------------------------------