I have a couple of large disks with backup/archive material on them. They're ext4. Regarding the ones of those that will be stored for a couple of years without reading the whole disc again I've been thinking of a way to refresh the disks magnetic state. Shelf life of drives seems to be a matter of debate everywhere I've been looking for an answer, but it seems after a couple of years (say 5 or so) of storage it would be wise to refresh the data in some way (?)
I've seen this suggested:
dd if=/dev/sda of=/dev/sda
Is it safe? Is it useful?
What I'm looking to do is another thing than a
fsck or a
dd if=/dev/sda of=/dev/null, both of which will probably discover existing magnetic drop outs on the disk.
What I want to do is to refresh the magnetic data before the magnetic charges on the disk lowers below a readable level. How can I do this?