Deleting of old backups in Time machine I have WD-My book world of 1TB and I struggled for some time to set it up correctly to use it as a disk for usage of time machine on Mac OS X Yosemite.

My question is the following-what is the best way to delete old backups as I don't want to eat up all the HDD with the backups. I'm more than enough with a 1 month old backups.

I read on Apple's website about the deletion on files on disk but as this is a NAS disk it's a bit different than a regular USB external HDD and it shows me only a lookalike of the "img file" (when I go to get info, it says "Sparse Disk Image Bundle") see screenshot:



What is your advice?
The sparsebundle is a disk image file and probably contains your Time Machine files. If you double-click it, it should be mounted. If not, launch Disk Utility and open it from there (File > Open Disk Image...). 

In order to delete backups, enter Time Machine, select a snapshot (time) and right-click in the Finder window. From there you can delete the snapshot by clicking Delete Backup. Watch out no more confirmation will be asked! You can also delete all backups / snapshots of a file or folder by selecting Delete All Backups of ....

If you are more the Terminal kind of person you can also use tmutil. This would look somewhat like this:

sudo tmutil delete /Volumes/Time_Machine_Disk/Backups.backupdb/computer/date/


You should only use these methods and not delete files manually from your mounted sparsebundle image.