Managing and Implementing Disaster Recovery (Backup Methods)

ronpasa69

Oh, my gosh. I know that it is not rocket science but I get so confused some times on the topics of Normal, Incremental and Differential backups. It should be really simple and it is, this has to be the only subject right now that I am really hoping isn’t that prevalent on the 70-290 exam. Any tips or tricks you can recommend. Any memory tricks. I know that Incremental and Normal clear the Archive bit and Differential set the Archive bit but I get confused when I'm asked to use the method that would require the less time. I learned that it is weekly normal backups and daily differential backups from 'Transcender'.

dynamik

Have you read the tech notes: http://techexams.net/technotes/xp/backup_restore_repair.shtml (I know it's for 270, but it's the same between XP and Server 2003)?

Differential would be the fastest since you'd only need to restore the last full backup and the last differential backup. If you were doing incremental backups, you'd have to restore the last full backup plus every incremental backup since. If you've only done one incremental or one differential backup since the last full backup, the restore time would be the same. However, if you've done a dozen of whichever one, you'd need to restore all twelve of the incremental backups while you would still only need to restore the last single differential backup. The downside of differential backups is that they take longer and require more storage space.

Tontonsam

For example, if you plan to do a normal backup every Monday and incremental the other days: On Monday, the normal backup copy all data. and each day, files that has not been backup since the last normal or incremental backup will be backup. So, with incremental backup it takes less time and less data is backup.
But if you plan do a normal backup every monday and differential the other days: On Monday, the normal backup copy all data and each day, files that has not been backup since the last normal backup (Monday) will be backup. So, it uses much space of data and much time.
Those are examples but you have to know the differences of them cause there are normal, incremental, differential, daily, copy backup.

meadIT

Here's the way I remember them:

normal - self-explanatory
incremental - I think of increments, or "little pieces"
differential - different, what has changed since the last normal backup
daily - self-explanatory...what changed today
copy - also self-explanatory...makes a copy without changing anything (archive bit)

ronpasa69

dynamik wrote:

Have you read the tech notes: http://techexams.net/technotes/xp/backup_restore_repair.shtml (I know it's for 270, but it's the same between XP and Server 2003)?

Differential would be the fastest since you'd only need to restore the last full backup and the last differential backup. If you were doing incremental backups, you'd have to restore the last full backup plus every incremental backup since. If you've only done one incremental or one differential backup since the last full backup, the restore time would be the same. However, if you've done a dozen of whichever one, you'd need to restore all twelve of the incremental backups while you would still only need to restore the last single differential backup. The downside of differential backups is that they take longer and require more storage space.

I love this web site and you guys so much. You put it so simply that I can understand and visualize the concept. I can not thank you enough.

Metaldave

It's a subject that I got quizzed on quite a bit on my exam.

It's one of those things that will just click one day.