The following section describes Business Copy EVA replication concepts.
Snapshots: A standard snapshot (full allocated) is a point-in-time virtual copy of the data, created in seconds and usable immediately, providing maximum flexibility for user applications. Disk capacity is reserved to accommodate the original size of the source volume.
Vsnaps: Virtually capacity free snapshots (demand allocated) allow the user to create a point-in-time copy, or demand allocated snapshot, of a specified Virtual Disk (LUN). Vsnap is similar to the standard snapshot (fully allocated) except that it does not reserve the same amount of disk capacity as the production volume being copied. The amount of disk capacity used by the copy volume will grow as data in the production volume changes over time or if the Vsnap is set to read/write, and data is written directly to the Vsnap. The result is that a Vsnap is a true space-efficient copy where capacity is not wasted reserving space. This saves valuable capacity and reduces workload by automatically using space as needed.
MirrorClone: MirrorClone provides an alternative to a snapshot by allowing the user to make a full, byte-for-byte, point-in-time copy of a source LUN that can be mounted to a secondary server. MirrorClone will track all changed blocks and can re-sync with the source LUN to create a new point-in-time copy, or can be used to instantly restore the source.
Snapclones: A Snapclone is a complete clone copy of a specified Virtual Disk (LUN). With traditional arrays, a clone can take hours to build depending on its size. Unlike traditional clones, HP Business Copy EVA Snapclones are available virtually immediately. Within a few seconds of when the Snapclone is taken, the entire clone copy is available for use. The Snapclone normalizes in the background so that no time is wasted waiting for the copy to complete. Enterprise Snapclones can also be taken in any redundancy level (RAID 0, 1, or 5). Snapclones provide the ability to take and use a clone without extensive advance preparation. Long "re-synch" times are also eliminated with Snapclones since a current clone copy can be available for use in minutes, not hours. Snapclones can also be created in different disk groups allowing users to copy the data to lower cost drives such as FATA.
Note:
Snapclone is available instantly while it normalizes in the background as opposed to the MirrorClone that is pre-normalized, and
MirrorClone has the ability to maintain its relationship with the source volume which it allows the ability to update quickly by only copying the changed data.
Cross Vraid Snapshot and Snapclones: EVA allows for increased flexibility and improved capacity utilization by supporting changing the Vraid type with Cross Vraid Snapshot and Snapclone, within the same disk group and Cross Vraid Snapclone across disk groups. Cross Vraid Snapclone also supports changing the Vraid type when Snapcloning from a high performance disk group to a FATA disk group.
Instant Restore: With the EVA4000/6000/8000 arrays, users can restore a source volume using a normalized Snapclone, MirrorClone, Snapshot, or any other Vdisk of the same size. This allows for quick recovery of a source should the volume become corrupted.
BC EVA uses
The following section describes Business Copy EVA uses.
Recover from disk ? HP Business Copy EVA offers the ability to instantly restore a source storage volume (Vdisk) with a fully normalized Snapclone, Snapshot1 or Vdisk of the same size. This advanced function allows an application to be brought back online quickly should a storage volume become damaged, or corrupted.
Backup ?HP Business Copy EVA together with Backup Solutions provide users with a complete, automated, non-disruptive backup solution. With this solution, users can effectively "eliminate the backup window" by making a snapshot or clone copy of the data to be backed up, mounting it to a backup server, and backing it up as a separate process from normal application processing. Application downtime can be reduced from many hours to a few seconds thus giving the user greater application availability.
Application testing ?A copy of production data can be made with a snapshot or clone and then mounted on a computer in a test environment. Since both snapshots and clones can be written to without affecting the actual production data, they are ideal for this application. If data is corrupted as a result of the testing, the copy can be deleted and another created.
Data Mining ?By creating a clone of production data, data mining processes can be run from the copy without impacting the performance of the production volumes.
Work Distribution ?Multiple clones of a single production volume can be made and then be used by a parallel processing application to greatly enhance processing作者: xiaomao2006 時(shí)間: 2008-10-08 17:03
答完了,飄過作者: cncqpansky 時(shí)間: 2008-10-08 17:23
