Summary
Each Xackup backup job has a Compression tab with four options. They differ in where the compression happens: on your Xen server, on the PC running Xackup, or both. That affects how long the backup takes, how big the backup is, and which machine does the work.
The four options
| Option | Best for | Backup time | Backup size |
|---|---|---|---|
| No Compression | Fast networks with plenty of storage | Shortest | Largest |
| Server Based Compression | Slower networks and servers with spare capacity | Short | Medium |
| Client Based Compression | Fast networks and a capable Xackup PC | Medium | Smaller |
| Client & Server Based Compression | Getting the smallest backups when time is not important | Longest | Smallest |
No Compression
The quickest option and puts the least load on your servers and PC. Backups take the most storage.
Server Based Compression
Your Xen server compresses the VM before it is sent, so less data crosses the network. This suits slower networks. It adds some load to the server while the backup runs.
If Allow ZStandard Compression if available is ticked, Xackup uses a faster, more efficient method when your server supports it. We recommend leaving it ticked.
Client Based Compression
The PC running Xackup compresses the backup as it is saved, giving a smaller backup without extra load on your server. Click Advanced Compression Settings to:
- choose a compression level. The default favours speed, and we recommend keeping it unless you have a reason to change it, as higher levels take noticeably longer for a small saving.
- set an optional password to protect the backup. Keep it safe, as you will need it to restore.
Client & Server Based Compression
Uses both for the smallest backups. It is generally the slowest option. It is only available when the backup is saved to a local location. If your Saved Location is on the network, the option is greyed out.
Which should I choose?
- Fast network, plenty of storage: No Compression.
- Slower or limited network: Server Based.
- Want smaller backups, and Xackup runs on a capable PC: Client Based.
- Smallest backups, time is not a concern, local destination: Client & Server Based.
Good to know
- Jobs set to Snapshots only have no Compression tab, as no backup file is created.
- You can change the option at any time. It applies to the next backup, and existing backups are not changed.
- When you restore, Xackup works out how a backup was compressed for you.
- If you are unsure, Server Based Compression is a good starting point for most setups.