fix #1818: use NTP instead of Servers in timesyncd.conf

[pve-docs.git] / vzdump.adoc

diff --git a/vzdump.adoc b/vzdump.adoc
index 6953fb9b66795c50b358b6fd24dbb9b48124fb66..193e1cfe23d8dfbbd9ac5f9b41524dd460be5eeb 100644 (file)
--- a/vzdump.adoc
+++ b/vzdump.adoc
@@ -111,7 +111,7 @@ started (resumed) again. This results in minimal downtime, but needs
 additional space to hold the container copy.
 +
 When the container is on a local file system and the target storage of
-the backup is an NFS server, you should set `--tmpdir` to reside on a
+the backup is an NFS/CIFS server, you should set `--tmpdir` to reside on a
 local file system too, as this will result in a many fold performance
 improvement.  Use of a local `tmpdir` is also required if you want to
 backup a local container using ACLs in suspend mode if the backup
@@ -147,18 +147,63 @@ That way it is possible to store several backup in the same
 directory. The parameter `maxfiles` can be used to specify the
 maximum number of backups to keep.
 
+[[vzdump_restore]]
 Restore
 -------
 
-The resulting archive files can be restored with the following programs.
+A backup archive can be restored through the {pve} web GUI or through the
+following CLI tools:
 
 
 `pct restore`:: Container restore utility
 
-`qmrestore`:: QemuServer restore utility
+`qmrestore`:: Virtual Machine restore utility
 
 For details see the corresponding manual pages.
 
+Bandwidth Limit
+~~~~~~~~~~~~~~~
+
+Restoring one or more big backups may need a lot of resources, especially
+storage bandwidth for both reading from the backup storage and writing to
+the target storage. This can negatively effect other virtual guest as access
+to storage can get congested.
+
+To avoid this you can set bandwidth limits for a backup job. {pve}
+implements two kinds of limits for restoring and archive:
+
+* per-restore limit: denotes the maximal amount of bandwidth for
+  reading from a backup archive
+
+* per-storage write limit: denotes the maximal amount of bandwidth used for
+  writing to a specific storage
+
+The read limit indirectly affects the write limit, as we cannot write more
+than we read. A smaller per-job limit will overwrite a bigger per-storage
+limit. A bigger per-job limit will only overwrite the per-storage limit if
+you have `Data.Allocate' permissions on the affected storage.
+
+You can use the `--bwlimit <integer>` option from the restore CLI commands
+to set up a restore job specific bandwidth limit.  Kibit/s is used as unit
+for the limit, this means passing `10240' will limit the read speed of the
+backup to 10 MiB/s, ensuring that the rest of the possible storage bandwidth
+is available for the already running virtual guests, and thus the backup
+does not impact their operations.
+
+NOTE: You can use `0` for the `bwlimit` parameter to disable all limits for
+a specific restore job. This can be helpful if you need to restore a very
+important virtual guest as fast as possible. (Needs `Data.Allocate'
+permissions on storage)
+
+Most times your storage's generally available bandwidth stays the same over
+time, thus we implemented the possibility to set a default bandwidth limit
+per configured storage, this can be done with:
+
+----
+# pvesm set STORAGEID --bwlimit KIBs
+----
+
+
 Configuration
 -------------