X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=vzdump.adoc;h=0461140de480509a551eb9c220d9be7cba2adc35;hb=3802f512b9733615ce60d31588fb2d3e13441a0c;hp=babf40727671a9fee0ffd78cf140aa2b29120078;hpb=d929c5a6260b0cb1aa4088d9d816f7c1ae5e2256;p=pve-docs.git

diff --git a/vzdump.adoc b/vzdump.adoc
index babf407..0461140 100644
--- a/vzdump.adoc
+++ b/vzdump.adoc
@@ -62,10 +62,11 @@ depending on the guest type.
 `stop` mode::
 
 This mode provides the highest consistency of the backup, at the cost
-of a downtime in the VM operation.  It works by executing an orderly
-shutdown of the VM, and then runs a background Qemu process to backup
-the VM data. After the backup is started, the VM goes to full
-operation mode if it was previously running.
+of a short downtime in the VM operation. It works by executing an
+orderly shutdown of the VM, and then runs a background Qemu process to
+backup the VM data. After the backup is started, the VM goes to full
+operation mode if it was previously running. Consistency is guaranteed
+by using the live backup feature.
 
 `suspend` mode::
 
@@ -89,7 +90,10 @@ https://git.proxmox.com/?p=pve-qemu.git;a=blob_plain;f=backup.txt[here].
 
 NOTE: Proxmox VE live backup provides snapshot-like semantics on any
 storage type. It does not require that the underlying storage supports
-snapshots.
+snapshots. Also please note that since the backups are done via 
+a background Qemu process, a stopped VM will appear as running for a 
+short amount of time while the VM disks are being read by Qemu.
+However the VM itself is not booted, only its disk(s) are read.
 
 .Backup modes for Containers:
 
@@ -143,18 +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
 -------------