Guidelines for Exchange Online Access Nodes

Updated

Verify that the access nodes for Exchange Online meet the guidelines. An access node is a virtual machine, a cloud instance, or a physical server that runs backups and other operations.

Note: For high availability (which is recommended for the first full backup), use 2 or more access nodes and extra Azure service accounts.

With Content Indexing

If you use content indexing, use the following guidelines.

Environment

Medium

Large

Mailboxes

5,000

10,000

Messages per day

500,000

1 million

Guidelines

Access nodes

  • Normal availability: 1

  • High availability: 2 or more

  • Normal availability: 1

  • High availability: 2 or more

CPU or vCPU for the access nodes

8 cores

16 cores

RAM for the access nodes

16 GB

32 GB

Streams per access node

10

20

Azure apps

5

10

Without Content Indexing

If you do not use content indexing, use the following guidelines.

Environment

Medium

Large

Mailboxes

5,000

10,000

Messages per day

500,000

1 million

Guidelines

Access nodes

  • Normal availability: 1

  • High availability: 2 or more

  • Normal availability: 1

  • High availability: 2 or more

CPU or vCPU for the access nodes

4 cores

8 cores

RAM for the access nodes

8 GB

16 GB

Streams per access node

10

20

Azure apps

5

10

Assumptions

The guidelines are based on the following assumptions:

  • The average mailbox size is 5 GB.

  • The average number of messages in each mailbox is 50,000.

  • The average message size is 100 KB.