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The backup appliance orchestrates snapshot, replica and backup operations. This is where you configure credentials, worker settings, backup repositories, policies, and can manage restore operations. As a control plane, several of the actual tasks are performed with workers. The appliance communicates with workers to perform the required tasks such as backup, restore, archive and retention operations.


If you want to change the appliance size you can change it during the deployment, however it is possible to change it after the deployment in case the environment grows.

The following recommendations and examples apply to the latest VBA builds 1.

Appliance Size Advised Maximum Number of Workloads
T3.medium (default - 2 vCPU, 4 GiB RAM) 1000
T3.2xlarge (medium - 8 vCPU, 32 GiB RAM) 5000
C5.9xlarge (large - 36 vCPU, 72 GiB RAM) 10000

In order to properly function, there are 3 parameters that define the appliance size (and more important, the amount of memory required).

  • OS utilization: the average value of memory needed in idle state which is around 1.5GiB
  • VBA utilization: 5% of the total appliance memory required for the VBA application (Web UI and REST API service)
  • Policies utilization: memory used per running policy. For more information on policy maximums, see the policies page

The policy utilization depends on their configuration and whether they only do snapshots or additional types of protection.

Policy Configuration Default Memory Used Additional Memory Per Workload
Snapshot Only 90 MiB 1 MiB
Snapshot and Replication 90 MiB + 20% 1 MiB
Snapshot and Backup 140 MiB 3 MiB
Snapshot, Replication and Backup 140 MiB 3 MiB

By combining all the above, the appliance size can be defined using the formula below which will calculate how much memory is required to operate.

OS utilization + VBA utilization + policies utilization

The below table contains some examples regarding the sizing of the appliance. The following applies to the table.

  • Working space: amount of memory free after calculation of the amount required for the operating system and VBA application
  • Workloads in policy: amount of workloads per policy
  • Number of policies: amount of policies you can run within the working space (recommended)
  • Memory consumed by all policies: total memory consumed by running all policies at the same time

Memory sizing examples

The below examples show some examples based upon a defined number of policies compared against the total appliance memory. This table is the maximum of memory usage when all policies would run at the same time.

In the table, we will use 140 MiB as a base per policy presuming that each policy has a snapshot, replication and backup schedule configured.

Total Appliance Memory Working Space Number of Policies Workloads per Policy Total Memory Consumed
4 GiB 4 GiB- 1.5 GiB
- 4 GiB * 0.05
= 2.3 GiB
5 50 (140 + (50 * 3)) * 5
= ~1.5 GiB
8 GiB 8 GiB- 1.5 GiB
- 8 GiB * 0.05
= 6.1 GiB
20 50 (140 + (50 * 3)) * 20
= ~5.8 GiB
16 GiB 16 GiB- 1.5 GiB
- 16 GiB * 0.05
= 13.7 GiB
25 50 (140 + (25 * 3)) * 50
= ~10.8 GiB
32 GiB 32 GiB- 1.5 GiB
- 32 GiB * 0.05
= 28.9 GiB
75 75 (140 + (75 * 3)) * 75
= ~27.4 GiB
72 GiB 72 GiB- 1.5 GiB
- 72 GiB * 0.05
= 66.9 GiB
300 25 (140 + (25 * 3)) * 250
= ~64.5 GiB

The main aspect of which will define how much memory you require for the appliance is how many workloads you want to configure within a specific policy. Veeam recommends to not size the appliance to the minimal limit but leave an additional margin of 20% RAM.

NOTE: The above information is only related to the OS, Veeam services and assurance to operate without issues. It does not take into calculations any additional software that may needs to be installed by company policies.

CPU sizing examples

The table below contains information on how many vCPU’s are required for the appliance based on the amount of workloads you want to protect.

NOTE: This only applies to snapshots and replication as the backup process is performed by workers.

Amount of vCPU Number of Simultaneous Snapshots
4 vCPU 500
8 vCPU 1000
16 vCPU 1800

Configuration restore recommendations

The following is especially recommended for large-scale deployments.

  1. There should be at least twice as much free space on the root disk as the size of the configuration backup file. If the backup file is 3GB, make sure you have at least 6GB of free space available.
  2. There must be at least twice as much free space on the database disk as the size of the database. This is by design as VBA will first first create a new database, and then delete the old one.

VBR integration

When integrating VBA with VBR, policy and retention data is imported into the VBR database.

You can connect more than one VBA appliance to a single VBR server, however make sure you size your VBR infrastructure appropriately. If working on a cross-geography cloud project it makes sense to use a VBR server per geo-region, to alleviate issues relating to latency as well and help with meet potential data residency regulations.

Logging enhancements

It is possible to configure logging options in the configuration file (/etc/veeam/awsbackup/config.ini).

LogLevel = "Normal"
LogsArchivesMaxCount = 100
LogsArchivesMaxSizeMb = 1000
WorkerLogsLifeTime = "36500:00:00:00"
WorkerLogsMaxArchivesCount = 2147483647
WorkerLogsMaxSizeMb = 2147483647

If you do run out of diskspace on the appliance due to the logs total size, it is possible to remove logs and zip files from the following folders.

  1. Veeam Backup for AWS or higher 

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