Loose Dedup Cache Matching

Loose deduplication caching is a feature that allows Alike to improve (initial) backup job times. In some environments, it can provide significant performance gains, nearly eliminating the initial backup "penalty".

With this option enabled, Alike is able to use a "similar" VM's backup as a source-side caching reference for a system's initial backup. Using this cache, Alike is able to avoid unnecessary many duplicate writes of data to the A2.

To prepare the dedup cache, Alike will attempt to select a backup of a similar VM, if available. A similar VM is considered one:

  • With the same operating system
  • With the same size, and number of disks

To best take advantage of this feature, it is recommended to complete a backup of a VM that can be used for caching on other systems. For example, if your environment has many VMs from the same base template, or image, then simply backup 1 of them completely, before moving on to backup all the others.

This option is enabled by default, and is considered completely safe. Even if Alike were to select a completely dissimilar VM for it's dedup cache, it would only result in no performance increase. Disabling this feature should only be necessary in cases of diagnosis, or troubleshooting.