Limit jobs per policy (policy attribute)
The attribute limits the number of jobs that NetBackup performs concurrently when the policy is run. By default, the box is unchecked, and NetBackup performs an unlimited number of backup jobs concurrently. Other resource settings can limit the number of jobs.
A configuration can contain enough devices so that the number of concurrent backups affects performance. To specify a lower limit, check the box and specify a value from 1 to 999.
This attribute operates differently for VMware policies, depending on how the policy selects virtual machines.
For more information, see the NetBackup for VMware Administrator's Guide.
Table: Factors affecting the number of concurrent backup jobs describes the factors that affect the number of concurrent backup jobs that NetBackup can perform.
Table: Factors affecting the number of concurrent backup jobs
Item | Description |
|---|---|
Jobs from different policies | The limit does not apply to concurrent jobs if the jobs are from different policies. For example, if three policies limit concurrent jobs to two, NetBackup can start two jobs from each policy. A total of six policies can be running at one time in this situation. |
Multiplexing | If multiplexing is used, set the limit high enough to support the specified level of multiplexing. Lower values can limit multiplexing within a policy if jobs from different schedules exist within the policy. For example, the limit is set to two and an incremental backup schedule is due to run for four clients. Only two clients are backed up at one time, regardless of the multiplexing settings. |
Network load | The available bandwidth of the network determines how many backups can occur concurrently. If you encounter loading problems, consider multiple networks for backups. Or, configure the backup policy to use the attribute. See Compression (policy attribute). When the client that is backed up is also a server, it is a special case. In this instance, the network load is not a factor because the network is not used. However, the load on the client and server is still a factor. |
Number of storage devices available and multiplexing limits | To process more than one backup job at a time, the configuration must include one of the following:
With removable media devices such as tape drives, the number of concurrent jobs depends on the total number of drives in the storage units. With disk storage, the storage device is defined as a file path and the available disk space determines how many paths are possible. |
Parent job and children jobs | Parent jobs do not count toward the limit. Only the children jobs count toward the limit. The following are examples of the jobs that produce a parent job and children jobs:
See About the Jobs tab. This attribute operates differently for VMware policies, depending on how the policy selects virtual machines. For more information, see the NetBackup for VMware Administrator's Guide. |
Server speed | Too many concurrent backups interfere with the performance of the server. The best number depends on the hardware, operating system, and applications that are running. |