Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Possible Duplicate:
Does built in Windows 7 backup perform differential (incremental) backups?

I am asking this question because the drive I have allocated for said utility to use as backup space is quickly filling (it's a 500GB drive) and this is unexpected to me since the amount of data I produce daily is very little (totally insignificant compared to the rate of use on said drive).

I have configured the utility to backup daily, at time t. The drive in question is a removable drive but it remains connected to the machine. I assume the answer to my question will note if the utility writes over the last backup when making a new one, or if it keeps all backups, etc.

share|improve this question

marked as duplicate by Ƭᴇcʜιᴇ007, Randolph West, 8088, Canadian Luke, Diogo Sep 15 '12 at 23:25

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

    
@techie007 - is this the same question? - although I agree the post you give is relevant and helpful, the post you give suggests that the W7 back up only backs up files that have changed - this doesn't answer why stuckey's file size is growing so much compared to how little changes he is making. –  Dave Rook Sep 14 '12 at 8:24

1 Answer 1

It sounds like you are using the wrong backup type.

If you are using the "daily backup" that is the source of the excessive size. A daily backup copies all selected files that have been modified the day the daily backup is performed. The backed-up files are not marked as having been backed up (in other words, the archive attribute is not cleared).

This means every backup you do, causes all the previous data to be backed up as well.

Typically in a scenario where you want to backup your data daily, you want to do a Normal backup on Monday and then an Incremental backup for the rest of the week.

A normal backup copies all selected files and marks each file as having been backed up (in other words, the archive attribute is cleared). With normal backups, you need only the most recent copy of the backup file or tape to restore all of the files. You usually perform a normal backup the first time you create a backup set.

An incremental backup backs up only those files created or changed since the last normal or incremental backup. It marks files as having been backed up (in other words, the archive attribute is cleared). If you use a combination of normal and incremental backups, you will need to have the last normal backup set as well as all incremental backup sets in order to restore your data.

When there is a loss of data, you would restore the normal backup, then the incrementals to get to return to the most current data.

share|improve this answer
1  
i'm not I understand what you mean by daily back up. I'm using the backup and restore utility and it doesn't have an option for daily back up. Task scheduler allows one to have backup and restore run daily. –  jhstuckey Sep 14 '12 at 6:42
    
hmm. when you mentioned daily backup I thought you might have installed the old backup tool. –  Keltari Sep 14 '12 at 6:44

Not the answer you're looking for? Browse other questions tagged or ask your own question.