Arq® Blog

Arq 5.11 released

Arq 5.11 is out for both macOS and Windows. The big change in this update is to validation.

“Validation” is the process by which Arq checks that every object referenced by the latest backup record still exists at the destination, and has the correct contents. Prior to 5.11, validation happened as part of the backup process, and it forced the backup process to single-threaded mode. This was very slow especially the first time it ran and especially for very large data sets.

In 5.11, Arq does validation separately from backups. It also validates the data using multiple threads. So, backups will continue to run with normal performance while validation is happening.

(How validation works is a longer story and will be the topic of a blog post coming soon.)

The update is free for all Arq 5 users. Please pick “Check for Updates” from Arq’s menu to get it, unless the auto-updater already installed it!

As always, if you have any questions, please email us at We’ll respond promptly.