From 922569a5bcc78ffdb69e8ca27a8ddb8cad61c393 Mon Sep 17 00:00:00 2001 From: Thomas Lamprecht Date: Thu, 22 Mar 2018 11:51:15 +0100 Subject: [PATCH] vzdump: add restore bwlimit docs Signed-off-by: Thomas Lamprecht --- vzdump.adoc | 49 +++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/vzdump.adoc b/vzdump.adoc index 6953fb9..03d6caa 100644 --- a/vzdump.adoc +++ b/vzdump.adoc @@ -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 to 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 ` 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 does not impacts +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. (Need `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 ------------- -- 2.39.2