Backups require specific compute resources (such as CPU and memory) and disk space. These requirements apply to scenarios that require a backup client, such as ECS file backup, local file backup, on-premises NAS backup, CPFS backup, archive, and data synchronization. They also apply to virtual machine backup, which requires a backup gateway. Evaluate your business scale and data volume to reserve sufficient resources.
Compute resources
The following table lists the minimum memory requirements for running a single task, based on tests in a lab environment. Actual memory usage may vary depending on file distribution, file count, and file size.
If available memory is insufficient, the backup task fails proactively to avoid impacting your production workloads.
Backup item | vCPU cores | Minimum reserved memory | |
on-premises NAS backup | 4 | 8 GB | |
CPFS backup | 4 | 8 GB | |
archive | 4 | 8 GB | |
data synchronization | 4 | 8 GB | |
local file backup | 2 | 4 GB | |
ECS file backup | 2 | 4 GB | |
ECS file backup (Basic) | High priority | 2 | 4 GB |
Low priority | 1 | 128 MB | |
virtual machine backup | 4 | 16 GB | |
Disk space
The definition of "backup node disk" varies by scenario. For on-premises operations, such as backing up servers, archiving data, or synchronizing data, it refers to the server's hard disk. For cloud operations, such as ECS file backup, CPFS backup, or cloud-based archiving and synchronization, it refers to the ECS instance's block storage, which includes local disks and cloud disks.
On-premises NAS backup, CPFS backup, archive, and data synchronization
You need only 1 GB of space for client installation (for the installation package and temporary logs).
Local file backup, ECS file backup, and ECS file backup (Basic)
When backing up files from an on-premises server or an ECS instance, the client installation and runtime cache consume disk space on the backup node. Ensure you reserve sufficient disk space on the disk where the backup client is installed.
Space for client installation: 1 GB is required for the installation package and temporary logs.
Backup runtime cache space: The cache stores backup metadata to accelerate backup jobs. Cloud Backup requires at least 1.5 GB of free space on the backup node disk. If you back up more than one million files, you must reserve an additional 0.5 GB of space for every additional one million files.
ImportantIf the free disk space is less than 1 GB, the file backup task fails and reports insufficient space.
The recommended reserved disk space is the sum of the space for client installation and the backup runtime cache space. Use the following formula to approximate the required space based on the number of files: 1 GB + 1 GB + 0.5 GB × .⌈Number of files / 1,000,000⌉
Number of files | Reserved disk space (GB) |
2 million | 3 GB |
5 million | 4.5 GB |
10 million | 7 GB |
Virtual machine backup
The disk space required for virtual machine backup depends on the disk's storage provisioning mode.
Virtual machine (thin provisioning): Requires 12.7 GB of space.
Virtual machine (thick provisioning): Requires 100.0 GB of space.