2007-01-28 20:13:42 · 3 answers · asked by Mike B 1 in Science & Mathematics ➔ Engineering
In the field of information technology, backup refers to the copying of data so that these additional copies may be restored after a data loss event. Backups are useful primarily for two purposes: to restore a computer to an operational state following a disaster (called disaster recovery) and to restore small numbers of files after they have been accidentally deleted or corrupted. Backups differ from archives in the sense that archives are the primary copy of data and backups are a secondary copy of data. Backup systems differ from fault-tolerant systems in the sense that backup systems assume that a fault will cause a data loss event and fault-tolerant systems assume a fault will not. Backups are typically that last line of defense against data loss, and consequently the least granular and the least convenient to use.
Since a backup system contains at least one copy of all data worth saving, the data storage requirements are considerable. Organizing this storage space and managing the backup process is a complicated undertaking.
A differential backup is a backup of every file on a file system which has changed since the last full backup.
The alternatives to a differential backup are incremental backup and full backup.
A differential backup can be an optimal middle-ground between a full backup and an incremental backup.
A differential backup is not as fast as an incremental backup, but it is faster than a full backup. A differential backup requires more storage space than an incremental backup, but less than a full backup. A differential backup requires more time to restore than a full backup, but not as much time to restore as an incremental backup.
2007-01-28 20:19:32 · answer #1 · answered by Jesus is my Savior 7 · 0⤊ 0⤋
A differential backup is a backup of every file on a file system which has changed since the last full backup.
The alternatives to a differential backup are incremental backup and full backup.
A differential backup can be an optimal middle-ground between a full backup and an incremental backup.
A differential backup is not as fast as an incremental backup, but it is faster than a full backup. A differential backup requires more storage space than an incremental backup, but less than a full backup.
A differential backup requires more time to restore than a full backup, but not as much time to restore as an incremental backup.
If you perform a full backup on Sunday and a differential every night, and the system crashes on Thursday, you will only need to restore the full backup from Sunday and the differential backup from Wednesday.
In contrast, if you perform a full backup on Sunday and incremental backups every night, when the system crashes on Thursday, you will need to restore the full backup from Sunday along with the incremental backups from Monday, Tuesday, and Wednesday.
A differential backup should be performed daily on production systems.
2007-01-28 20:21:02 · answer #2 · answered by sanjaykchawla 5 · 0⤊ 0⤋
the backup application presented through domicile windows isn't as finished or grant diverse ideas as some application courses you should purchase. Norton ghost is an celebration - i am going to make an image of my hardchronic and shipment that image on as would diverse complicated drives as i ought to like - if the unique hardchronic became partitioned - Norton will partition the recent hardchronic instantly away the position with domicile windows you'll go with to partition the recent hardchronic in the previous you fix your backup.
2016-10-16 06:09:05 · answer #3 · answered by Anonymous · 0⤊ 0⤋