Dell PowerVault DL2000 - Manual (Page 10)

Table 1-3 DL Appliance configuration policies
Description Configuration policy
With the Automatic with confirmation policy, Backup Exec
first determines the total amount of disk space that is available
in a disk group. It then prompts you to confirm the creation
of striped with parity virtual disks. In addition, if slot 0
contains a physical disk, Backup Exec designates the physical
disk as a hot spare.
With the Automatic without confirmation policy, Backup Exec
determines the total amount of disk space available in a disk
group. It then creates the striped with parity virtual disks
with no user action required. In addition, if slot 0 contains a
physical disk, Backup Exec designates the physical disk as a
hot spare.
The total amount of disk group space determines the number
of virtual disks that Backup Exec creates. The maximum size
of each virtual disk that Backup Exec creates is two terabytes,
depending on the total capacity of the disk group. When you
review storage array capacities after Backup Exec creates all
virtual disks, note that parity calculations generally use
storage space equal to one physical disk.
For example, for a disk group that is formed from seven 1TB
physical disks and has a total capacity of seven terabytes,
Backup Exec creates three virtual disks. Each virtual disk has
a capacity of two terabytes. After the virtual disks are created,
you have six terabytes of total storage capacity. In this case,
one terabyte of unallocated space is reserved for parity
calculations.
For a disk group that is formed from seven 500GB physical
disks and has a total capacity of 3.5 terabytes, Backup Exec
creates two virtual disks. Each virtual disk has a capacity of
1.5 terabytes. In this case, Backup Exec reserves 500GBs of
unallocated space for parity calculations. Parity ensures that
if one physical disk fails, data is not lost.
Note: Dell recommends that you populate the enclosure with
physical disks of the same capacity. If you use physical disks
with different capacities, the result is wasted physical disk
space. Wasted disk space occurs because the disk group's total
storage capacity is calculated based on the physical disk with
the least capacity. It is not calculated based on the aggregate
capacities of each physical disk.
Automatic with
confirmation
Automatic without
confirmation
Introducing the Dell™ PowerVault™ DL Backup to Disk Appliance and the Backup Exec Storage Provisioning Option
About the DL Appliance configuration states and configuration policies 10