Worker Instances

If you want initial full backups to be processed quickly, it is recommended to use a larger worker profile, and then change it to a smaller profile for incremental backup. You can change worker profile settings on a regional basis, so make sure that the Azure VM sizes of worker instance size is appropriate to process the largest workload within the required time.

Each worker instance is deployed as an Ubuntu image, and the binaries are downloaded from the provisioning Azure storage account. Azure VM sizes of worker instances depend on the total size of virtual disks attached to the processed Azure VM or the total size of the processed Azure SQL database.

Profile	Azure VM Size	Case	Backup Speed
Small	F2s_v2	Backing up workloads with disks smaller than 100 GB (default)	70-85 MBps
Medium	F4s_v2	Backing up workloads with disks between 100 GB and 1 TB (default)	90-100 MBps
Large	F8s_v2	Backing up workloads with disks over 1 TB, also recommended for initial full backup (default)	125-140 MBps
Archiving	E2_v5	Data tiering (default)	85-110 MBps

For more information on Azure VM pricing, see Microsoft Docs.

Recommended Maximums

You can modify the default number of worker instances to reduce the amount of processing time, and choose profiles that will be used to launch worker instances in the selected regions to boost operational performance. For more information, see Adding Worker Profiles.

Purpose	Recommended Maximum Number of Worker Instances
Default appliance size	50
Medium appliance size	250
Large appliance size	500
Maximum per region per appliance	1,000
Service bus (2 queues per worker, based on the default basic tier)	5,000
Azure ARM API reads (per tenant/user/hour)*	12,000
Azure ARM API writes (per tenant/user/hour)*	1,200

*For more information on the Azure Management API request limits and throttling, see Microsoft Docs.