X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=vzdump.adoc;h=1c396804f0cf9b08c8d8bc44231d4a760778acc6;hb=0fb9147a6559adb2890ef028c58b3206cf4211b7;hp=e990982c9c6df501df3ed29f6b8c788f2044baca;hpb=b26b1d126d0795670a91a628ce209c712134565c;p=pve-docs.git diff --git a/vzdump.adoc b/vzdump.adoc index e990982..1c39680 100644 --- a/vzdump.adoc +++ b/vzdump.adoc @@ -78,17 +78,17 @@ consistency, the use of the `snapshot` mode is recommended instead. `snapshot` mode:: This mode provides the lowest operation downtime, at the cost of a -small inconsistency risk. It works by performing a Proxmox VE live +small inconsistency risk. It works by performing a {pve} live backup, in which data blocks are copied while the VM is running. If the guest agent is enabled (`agent: 1`) and running, it calls `guest-fsfreeze-freeze` and `guest-fsfreeze-thaw` to improve consistency. -A technical overview of the Proxmox VE live backup for QemuServer can +A technical overview of the {pve} live backup for QemuServer can be found online 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 +NOTE: {pve} live backup provides snapshot-like semantics on any storage type. It does not require that the underlying storage supports snapshots. Also please note that since the backups are done via a background Qemu process, a stopped VM will appear as running for a @@ -147,6 +147,39 @@ 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. +Backup File Compression +----------------------- + +The backup file can be compressed with one of the following algorithms: `lzo` +footnote:[Lempel–Ziv–Oberhumer a lossless data compression algorithm +https://en.wikipedia.org/wiki/Lempel-Ziv-Oberhumer], `gzip` footnote:[gzip - +based on the DEFLATE algorithm https://en.wikipedia.org/wiki/Gzip] or `zstd` +footnote:[Zstandard a lossless data compression algorithm +https://en.wikipedia.org/wiki/Zstandard]. + +Currently, Zstandard (zstd) is the fastest of these three algorithms. +Multi-threading is another advantage of zstd over lzo and gzip. Lzo and gzip +are more widely used and often installed by default. + +You can install pigz footnote:[pigz - parallel implementation of gzip +https://zlib.net/pigz/] as a drop-in replacement for gzip to provide better +performance due to multi-threading. For pigz & zstd, the amount of +threads/cores can be adjusted. See the +xref:vzdump_configuration[configuration options] below. + +The extension of the backup file name can usually be used to determine which +compression algorithm has been used to create the backup. + +|=== +|.zst | Zstandard (zstd) compression +|.gz or .tgz | gzip compression +|.lzo | lzo compression +|=== + +If the backup file name doesn't end with one of the above file extensions, then +it was not compressed by vzdump. + + [[vzdump_restore]] Restore ------- @@ -200,10 +233,10 @@ 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 +# pvesm set STORAGEID --bwlimit restore=KIBs ---- - +[[vzdump_configuration]] Configuration -------------