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Re: "Invalid arch-independent ELF magic" in grub after SSD migration

> using something like rsync, which means no duplicate UUIDs, you aren't
> spending time copying sectors that aren't referenced, the SSD gets
> fewer write cycles and it can be interrupted and resumed.

FWIW, copying files has its own form of overhead, so if the drive is
reasonably filled, it'll be faster to do a `dd` than an `rsync` (because
that uses the optimal (sequential) access) and it might very well result
in fewer writes for the flash memory of your SSD.

Anyway, another advantage of `rsync` is that it works even if the
file-system is currently mounted and accessed.  E.g. I've cloned running
Debian systems with `rsync` with no problem, whereas doing it with `dd`
invariably leads to corrupted partitions.

> Or pvmove in some cases.

Personally I very rarely copy whole drives, but I do copy partitions
with `dd` sometimes (especially partitions with many small files where
`rsync` slows down noticeably).
Tho if I can use pvmove, that's a better option.