How big should my ext hdd be

[chuckycheeze]

I need to buy an external usb western digital hardrive and I wonder if I have 250 gig in my internal hardrive in my computer , will I be ok with 160 gig external hdd or does it have to match the one inside gig for gig 250 gig in order to use retrospect pro 7.0 succesfully ?

[RonaldL]

Well it depends on how much actual data you have on your 250 gig harddrive as well as how far back you want to keep backups for. The initial backup will take up the same amount of space on the external harddrive (maybe a little less if you turn on compression). If you do normal backups to it, Retrospect will append the new or changed files to it each time, so the backup set will slowly get bigger.