[CentOS] Mirroring Disk (Apologies for the new thread I deleted the original)

Answers to questions...

It really depends on your use case.

I'm looking to be able to pull out old dead drive, and replace it with
new (almost up to date) drive and reboot.

The USB disk is a 1TB disk in a case.

> Been considering dump and restoring to the usb disk periodically? or
> maybe something using LVM or maybe creating and breaking a RAID 1
> array?

Constantly making and breaking a RAID1 with a USB drive is probably not
helpful.  It's just more wear and tear on the OS drive, because it has
to be constantly read in order to mirror the target drive, and your USB
drive is probably not what you want to boot off of if your system drive
fails.  You'd be much better off with a permanent RAID1, but if you
can't do that then at least make a RAID1 to a USB enclosure which
contains the same size and interface drive as your current system disk.
This way if it fails you can swap in the backup drive and not have to
boot from a USB drive.

Yeah I thought that would be the case, as I said above I'd like to be
able to boot from the USB enclosure but the plan is to replace the
failed internal with the disk from the USB enclosure.

Would LVM be any help or is it just a complication? I defiantly
leaning to the nightly dump/restore into a similarly formatted disk.