HP D2D100, Руководство пользователя

Страница: 22 / 176

RAID
RAID stands for Redundant Array of Inexpensive (or Independent) Devices, which is a data storage
scheme that divides data among multiple hard drives, increasing data reliability and throughput. The
HP D2D Backup System is a RAID 5 device, which offers the best combination of data protection and
capacity. It has four hard disks, but if one of the disks fails, no data is lost and the HP D2D Backup
System continues to operate correctly. The failed disk should always be replaced as soon as possible.
Replication
Replication is a standard term used to describe a way of synchronizing data between hardware in two
physical locations. HP D2D Replication allows users to replicate data from cartridges on one HP D2D
Backup System to mapped slots on another HP D2D Backup System on a remote site or the same system.
Once con fi gured (using the simple-to-use wizard), replication occurs automatically, ensuring data is
mirrored from the source to the target HP D2Ds. Deduplication ensures that network traf fi c is minimized.
See also “ Con fi guring and using replication ” on page 59.
Tape Attach
If you attach a supported, physical tape library or tape drive directly to your HP D2D Backup System,
you will be able to copy or export data to the physical tape library or tape drive so that backups can
be stored offsite. This is an important requirement for Disaster Recovery strategies. The main difference
between copy and export is that copied data remains on the HP D2D Backup System; exported data
is removed from it, but can be imported easily when required. These functions are grouped under the
Tape Attach section of the Web Interface. Please see “ Using Tape Attach ” on page 121 for more
details about working with Tape Attach.
Storage capacity
Physical storage
The physical storage capacity of the HP D2D Backup System is 3.0 TB (3000 GB). However, in order to
ensure a high level of data integrity, the disks use RAID 5 protection. This reduces the available capacity
but ensures that, in the event of a single disk failure in the device, there will be no data loss.
Actual storage capacity is approximately:
• 2.25 TB for the HP D2D Backup System
Data deduplication is enabled by default for each library device. This eliminates duplicate data from
backups and means that more histories of data can be stored and retained for longer on each library.
See also “ Data deduplication ” on page 23.
You cannot add physical disk space, but you may be able to create some space. Options for creating
space, if the disks start to get full, are:
• Review your backup jobs to see if you can reduce the size of backup or retention time.
• Use the backup application job settings to overwrite or erase data.
• Export cartridges to physical tape.
Tape rotation strategies
Tape rotation strategies determine when backups are run, the number of cartridges that are required and
how they are reused. The HP D2D Backup System is a very fl exible device that can easily be incorporated
into most tape rotation strategies. If your organization does not yet have a tape rotation strategy in place,
see “ Tape rotation example with deduplication ” on page 24 for example con fi gurations.
22
Before you start