Veeam Backup & Replication caches data that is being retrieved from external repositories every time a backup copy job or restore session is performed.
Such an approach helps not only to reduce the amount of cost-expensive operations incurred by Amazon AWS or Microsoft Azure, but also decrease the amount of traffic being sent over the network.
Consider the following:
- Cache is created on a gateway server while the following activities are being processed:
- Backup copy jobs.
- Restore sessions.
- Cache is not created upon the addition of an external repository to the Veeam Backup & Replication console.
- Cache consists of metadata of blocks being retrieved from external repositories.
- Cache is written to:
- On a Windows-based gateway server: C:\ProgramData\Veeam\ExternalCache
- On a Linux-based gateway server: /var/veeam/ExternalCache
- Cache is reused and updated during each subsequent execution of a backup copy job or restore session.
- Cache size limit is 10GB. Once reached, Veeam will purge obsolete cache by 20% preserving most frequently used parts. Purging is done by the maintenance job.
- Cache is removed in the following cases:
- An external repository has been removed from the Veeam Backup & Replication console.
- The gateway server has been changed in the settings of the external repository configuration.
- The backup file has been removed from the external repository.
- During the maintenance job session.
- Cache can be removed manually without affecting the backup infrastructure in any negative way.