Learn more on Data protection using remote mirroring
Instant copies help to quickly restore data in the event of application or operating errors;however, they are ineffective in the event of a catastrophe: after a fire the fact that there
are several copies of the data on a storage device does not help. Even a power failure
can become a problem for a 24 × 7 operation.
The only thing that helps here is to mirror the data by means of remote mirroring
on two disk subsystems, which are at least separated by a fire protection barrier. The
protection of applications by means of remote mirroring has already been discussed in
detail in Sections 6.3.3 and 6.3.5.Nevertheless, the data still has to be backed up: in remote mirroring the source disk
and copy are always identical. This means that if data is destroyed by an application or
operating error then it is also immediately destroyed on the copy. The data can be backed
up to hard disk by means of instant copy or by means of classical network back-up to
tapes. Since storage capacity on hard disks is more expensive than storage capacity on
tapes, only the most important data is backed up using instant copy and remote mirroring.
For most data, back-up to tapes is still the most cost effective.
No comments:
Post a Comment