Developing Performance Factors
It is recommended that you develop performance estimation factors for various job types. This will help in planning, designing and scheduling new jobs.
Replication Speed
The snapshot method is virtually instantaneous for all types of storage units, regardless of size.
The length of time required to replicate units using the clone method varies from nearly instantaneous, up to hours. The main factors include the unit size and amount of I/O activity.
Storage units that are pre-configured as three-member (or more) mirror sets can be cloned nearly instantaneously during an EVM job.
EVM-Backup Job Length
In most cases, the length of the tape backup is the longest element in an EVM-backup job. Because of this, it is recommended that you run the EVM-and-backup job combination in such a way that the EVM job can start the tape backup and then end. This allows another EVM job to be started while the tape backup is running.
When creating the EVM job, you can use the EVM Job Mode selections to achieve this result. When you select the tape backup computer and specify the backup command, choose the Don't Wait mode. This will cause the EVM job to start the tape backup and then end. For more information see Create EVM Job, Step 6.
Undo-job Speed
When an EVM undo-job is run, it returns settings and disk resources to the configuration that existed just before the job started. In most cases, this is quickly accomplished by returning disks to the pool of free resources.
Undo-jobs for three-member storage units must reattach the split member to the original members and normalize them. The normalization step of the undo-job can take from minutes to hours.