if i want to use my external back-up drive for storage as well as back up in case my computer crashes... how do i make time machine save files that i have deleted from my computer's hard drive?
does time machine re-back up files that are already on the hard drive and waste space or just fill in the blanks when i add new files to my computer?
Mac OS X (10.7.2), Time Machine
If you want to use part of your backup drive for storage then partition the drive into two volumes. Remember a Time Machine backup volume should be at least twice the capacity of the drive backed up. Time Machine is a form of archival backup utility.
how do i make time machine save files that i have deleted from my computer's hard drive?
You cannot. Anything you delete from your main drive will eventually be deleted from Time Machine. If you want additional storage for stuff that does not fit in your main drive DO NOT use Time Machine as its home.
does time machine re-back up files that are already on the hard drive and waste space or just fill in the blanks when i add new files to my computer?
Any file that has NOT changed between 2 Time Machine backups will ONLY get a pointer to the file's copy in the previous backup, which might be a pointer to its previous backup, etc... If a file changes (or new files are added) between Time Machine backups, then the file will be copied into the next Time Machine backup.
So you might have only 1 real copy of a file in a Time Machine backup if it has never changed.
When older backups are removed, the pointers to the files in the backup are decremented. If any file's or directory's number of file pointers goes to zero, then the file is deleted. As long as one pointer still exists, the file will remain in the Time Machine backup.
In file system nomenclature, these pointers are called "Hardlinks" (hard links).
time machine- storage?
