which is best backup process to take shared hosting backups to external location.
best= reliable, cheap, easy management
Are you looking for the solution for your own web site of for the customers of you?
If you are talking about dedicated sever I suppose there is nothing better then RAID
raid has nothing to do with backup. it can save you from downtime during hardware failure.
backup or taking backups of backup is a separate task and it is really important thing in hosting biz which people ignore mostly.