What sort of disks to usefor backup

What sort of disks to usefor backup
Sorry - Version 6.

I do general backups to external hard drive Some things I do back up to optical disk - I've been using Dual-layer DVD for that quite a while now, since the capacity is greater than other optical media, but any high quality writable optical disk, CD or DVD, should be OK - I recommend you stick with name brands, and mebbe experiment a bit; some burners work better with some brands of disk. Generally, its best, IMO, to back up critical stuff to write-onece disks; RW disks have some potential for data corruption, particularly after multiple rewrites.

Use branded Grade A dvd's (As long as you have a dvd writer), personally i would recommend buying a portable hard drive to back up, easy to use and pretty reliable.