Does "Normal Backup Performance" actually write ALL blocks, even unchanged blocks? If so, why?
Per this link: https://technet.microsoft.com/en-us/library/dd759145.aspx?f=255&MSPPError=-2147217396, If "Normal Backup Performance" is selected, then "ALL of the contents are transferred... but space used is only associated with changed blocks"
This leads me to believe that ALL blocks are written; not only are changed blocks replaced in the backup, but also unchanged blocks are overwritten with the exact same blocks from the source. Is this correct?
If the above is correct, why overwrite the unchanged blocks? If this were a traditional full + incremental scenario I could understand wanting a single new full backups for quickly restoring rather than the time consuming process of restoring a full backup followed by a bunch of incrementals. But since WSB always has a full backup as the latest backup and never needs to restore a bunch of incrementals, I see no advantage of ever using the Normal Backup Performance option. Am I misunderstanding? If not, what is a reason to select the Normal Backup Performance option?
Per this link: https://technet.microsoft.com/en-us/library/dd759145.aspx?f=255&MSPPError=-2147217396, If "Normal Backup Performance" is selected, then "ALL of the contents are transferred... but space used is only associated with changed blocks"
This leads me to believe that ALL blocks are written; not only are changed blocks replaced in the backup, but also unchanged blocks are overwritten with the exact same blocks from the source. Is this correct?
If the above is correct, why overwrite the unchanged blocks? If this were a traditional full + incremental scenario I could understand wanting a single new full backups for quickly restoring rather than the time consuming process of restoring a full backup followed by a bunch of incrementals. But since WSB always has a full backup as the latest backup and never needs to restore a bunch of incrementals, I see no advantage of ever using the Normal Backup Performance option. Am I misunderstanding? If not, what is a reason to select the Normal Backup Performance option?