On 4/1/20 8:15 AM, Wols Lists wrote:
On 01/04/20 07:03, Daniel Jones wrote:
Thanks Phil,
I'll read this a couple of times and try some commands (likely on an
overlay) tomorrow.
If you CAN overlay, then DO. If you can't back up the drives, the more
you can do to protect them from being accidentally written to, the better.
I have to admit that I pretty much never use overlays. But then I'm
entirely confident of what any given mdadm/lvm/fdisk operation will do,
in regards to writing to devices. And since it is burned into my psyche
that raid is *not* backup, only an uptime aid, I keep good external
backups. (:
Lacking confidence and lacking backups are both good reasons for using
overlays. I'm not entirely sure the mental effort for a novice to learn
to use overlays is time better spent than learning enough about MD and
mdadm for confident use.
I do think initial recovery efforts with --assemble and --assemble
--force do not need to be done with overlays. They are so safe and so
likely to quickly yield a working array that I think overlays should be
recommended only for invasive tasks needed after these --assemble
operations fail.
--create is a very invasive opertion.
Phil
