A device pool is a group of devices that enables load-balancing of Backup Exec jobs sent to the same device pool for processing. The jobs are spread among the devices in a pool so that the workload is shared among the devices.
When you submit a backup job to a device pool, the job is automatically sent to the first available device in that device pool. As other jobs are created and started, they can run concurrently on other devices in the device pool. By dynamically allocating devices as jobs are submitted, Backup Exec processes jobs quickly and efficiently.
Devices can belong to more than one device pool, unless a device is in a cascaded drive pool. Device pools can contain different types of devices, including specific devices in multi-device robotic libraries.
You can assign priorities to devices in a device pool so that a specific device is used before other devices in the device pool. The priority assigned to a device in one device pool is unrelated to that device's priority in any other device pool. For example, if Device 1 is placed in both Device Pool A and Device Pool B, you can assign different priorities to it in each device pool. Device 1 can have a high priority in Device Pool A and a low priority in Device Pool B.
You can send backup jobs to specific devices in a device pool. However, if that device is busy, the job must wait until the device becomes available. When a specific device is assigned, the job cannot be automatically routed to the next available device.
Device pools also provide automatic job rescheduling. For example, if a device pool contains four stand-alone drives and the first device fails because of a hardware error, the job that was running on the failed device is resubmitted and placed on hold, and the other jobs are automatically routed to the working devices in the device pool.
In a device pool, Backup Exec selects the oldest recyclable media in all of the devices in the device pool to use first. If more than one media that meets the requirements is found, Backup Exec then searches the devices in a device pool according to device priority and uses the oldest recyclable media in the device that has the highest priority.
All Devices (Server Name) is the default device pool, created when Backup Exec is installed. All devices recognized by Backup Exec at startup are automatically assigned to All Devices (Server Name). Backup Exec excludes devices and simulated tape libraries on Remote Media Agents from All Devices (Server Name).
For a new installation of Backup Exec that includes the Storage Provisioning Option, the default device pool is the All Virtual Disks device pool.
You can create other device pools to meet your particular requirements, and assign and reassign devices to these pools. For example, you may want to separate high-performance devices from lower performance devices in a separate device pool in order to send high-priority jobs to the fast device pool for quicker completion.
About the All Virtual Disks device pool in the Storage Provisioning Option