I have two drives (E and F) on my WHS that are backed up daily at different times to the same backup target. Are my assumptions at the bottom correct?
- WHS 2011 with E and F data partitions both having 1TB data.
- Use wbadmin/task scheduler, E and F separately backed up daily to the same local target drive (X)
Monday, 1:00am: 1TB E backed to vhd.
Monday, 3:00am: 1TB F backed to vhd. 1TB E moved from vhd to shadow copy. Tot shadow = 1TB
Tuesday, 1:00am: 1TB E backed to vhd. 1TB F moved from vhd to shadow copy. Tot shadow = 2TB
Tuesday, 3:00am: 1TB F backed to vhd. 1TB E moved from vhd to shadow copy. Tot shadow = 3TB
And so on....
Assumptions - Are they correct:
1. During a backup, any previously backed up data in the vhd that is different from that being backed up, will be moved to the shadow copy area on the backup drive.
2. Since 2 drives are backed up separately to the same target, each backup's data will be completely different from that in the vhd. So even if I've only changed one file on E, a backup of E will write the full volume to the vhd because E data is compared only to the vhd (which contains only F data) and not to the previous version of E data (which is in shadow copy).
3. The shadow copy storage will be huge for only a few backups. It appears that I should have E and F backup to separate target drives to prevent this.