VBO Proxy sizing depends on the total number of objects to protect. Check out the Configuration Maximums to see how many proxies can be used and how many objects each of them can handle. Objects can be any combination of Mail, Archive, Site, OneDrive and Teams.
When sizing the VBO Proxies there are two important VBO parameters to know about:
- Number of threads
- Amount of bandwidth
It is the number of active connections started by the VBO Proxy responsible for backing up data. This number goes from 0 to 256. The higher the number the faster potentially the backup job will complete. Default number of VBO Proxy connections is 64. Although it is possible to change this number, using a thread number too high might incur in the Throttling Policy that Microsoft Office 365 activates to control the resources external clients/connection require. The advice is to monitor same sample “test jobs” to verify and adjust the number of threads. Very high CPU and memory load is a indicator for a misconfigured (too high) thread number.
Represents the network throughput shared across the number of configured threads. By default is set to unlimited. In this case all the available bandwidth to the server running as VBO Proxy will be used. The best practice is to limit the maximum amount of bandwidth the VBO Proxy can use. It is interesting to note the VBO Proxy might not necessarily use the maximum bandwidth configured as this also depends on the Office 365 throttling limiting the connection speed. In any case the bandwith is always shared across the number of threads.