[Borgbackup] Performance of using Borg on SMR drives

[Marian Beermann]

Did someone try this yet?

>From reviews like
http://www.tomsitpro.com/articles/seagate-8tb-archive-hdd-review,2-822-3.html
I take it that the banded nature of a device-managed SMR drive means
that low-concurrency sequential writes and no overwrites are best for
these drives -- just like Borg does.

However, I think the 5 MiB segment size (+fsync) used in 1.0.x might be
very bad for performance here (since the bands are larger than 5 MiB).
500 MiB (1.1.x) works maybe better there.

Cheers, Marian