Size guidance for the NetBackup primary server and domain
NetBackup primary server sizing is an important activity as part of an overall NetBackup solution design. Veritas always recommends a comprehensive data protection assessment to determine the optimal configuration for a NetBackup primary and NetBackup domain.
The following information is meant as guidelines:
NetBackup has no hard limit on catalog size. However, Veritas recommends as a best practice that you keep the catalog size under 4 TB to ensure good catalog backup and recovery performance.
The size of the NetBackup catalog and the performance that is related to reading data from the NetBackup catalog is driven by the I/O performance and more specifically the disk speed. Veritas recommends the use of solid-state drives (SSDs) where possible for the catalog. The disks require good read and write performance, which is even more critical in large environments.
Managing the size of the catalog through compression and catalog archiving is recommended for images with a long-term retention (LTR).
The number of devices in the EMM database should not exceed 1500.
Examples of devices are a tape drive, a tape library, a disk pool, and so on.
The number of media servers should not exceed 50.
It is important to maintain a manageable number of media servers and storage targets within each NetBackup domain. Every media server and storage target that is deployed must be managed, maintained, and eventually patched and upgraded. Each of those media servers has a configuration that has to also be maintained. Therefore, it is important to consider the manageability, usability, and the administrative implications. Veritas recommends deploying media servers and storage targets that are properly sized with the necessary CPU, memory, network bandwidth, and disk I/O to support the backup workloads. It is also important to consider whether the same workloads require duplication or replication to a DR location. Sizing the media servers and storage targets to accommodate those secondary options is crucial. In summary, Veritas recommends that you deploy properly sized media servers and storage targets, while keeping the number less than 50 per domain.
The number of jobs must not exceed one job per second per client, but it is possible to submit multiple jobs per second, each sent from a different client. Each backup client has the "one job per second per client" limit, so multiple clients may run in parallel.
Computing resources such as CPU and memory affect how well the primary server scales.
To accommodate the processing of the metadata streams from media servers, it is critical that the primary server has the requisite amount of system resources. A media server sends metadata about the files it has backed up to the primary server. This metadata is batched and sent periodically. The batch size, which is determined by the tuning parameter MAX_ENTRIES_PER_ADD, has significant effect on primary server performance, especially for backup images that contain many small files.
See Adjusting the batch size for sending metadata to the NetBackup catalog.
The primary server must then process each of these metadata message payloads. Each payload requires an operating system process, each of which consumes system resources. The consumed system resources are disk capacity, CPU cycles, memory capacity, network bandwidth, and disk I/O.
Table: Sizing guidelines provides additional information.
Table: Sizing guidelines
Number of processors | Recommended memory requirement | Maximum number of media servers per primary server * |
|---|---|---|
8 | 128 GB | 20 |
16 | 256 GB | 100 |
*Veritas recommends that you limit the number of media servers to less than 50 media servers per domain.