Topics | How To | Related Topics
When to Schedule Data Protection Operations
Scheduling Data Protection for Subclients, Backup Sets or Instance Level
Scheduled data protection operations provide a convenient means of securing data without user intervention. You can establish data protection schedules for each subclient using the CommCell Console, as described in the online help. When scheduling data protection operations, you need to establish a schedule for each subclient.
For example, a backup schedule always contains a full backup and may contain one or more other backup operations. When combined for a given subclient, these backups comprise a full backup cycle.
The following types of data protection operations can be scheduled:
Data protection operations, like other processes, consume system resources. The extent to which any given operation affects other applications depends on several factors:
We suggest that you schedule regularly occurring data protection operations for times of low system utilization. For example, you may want to avoid backing up or migrating data during office hours. If the data must travel across a network to reach the destination library, then scheduling operations during off-peak hours can be even more important since launching many operations simultaneously could diminish network responsiveness. The extent, if any, to which network responsiveness is degraded depends on a number of issues including the quantity of data being secured concurrently, capacity of the network, network configuration, etc.
It is often prudent to distribute the scheduled operations in a CommCell over some period of time in order to avoid media drive and media group contention. The length of time for any particular CommCell depends on the amount of data to be secured and the specific configuration of the CommCell with respect to libraries and storage policies. If the number of media drives is small compared with the number of subclients in the CommCell, drive contention can occur. If the number of storage policies is small compared with the number of subclients, or if a specific storage policy is the target of many subclients, then media group contention can occur. (Media group contention is discussed in Media Contention within Removable Media Groups.) If either condition occurs, data protection operations will queue until the needed resource becomes available. Consequently, operations may extend beyond the operation window that was intended for the CommCell.
The system allows you to schedule or initiate backups at the subclient, instance and/or backup set level depending upon the agent. Selecting the backup set or instance saves you from having to select the individual subclients. If you select a backup set or instance, the system applies the same schedule or data protection operation request to all constituent subclients.
Remember that the rules for initiating operations of sibling subclients still apply. If the subclients within a backup set or instance are mapped to the same storage policy, and if that storage policy is not configured for multiple data streams, then the system queues the operations and performs one data protection operation at a time. For more information, see Establishing Parallel Data Protection Operations Using Subclients.