Re: [BUG] non-metadata arrays cannot use more than 27 component devices

[Wols Lists <antlists@youngman.org.uk>]

On 25/02/17 22:00, Phil Turmel wrote:
>> This is all a rather important usage of raid, actually, imho. It
>> > seems so obvious - create a temporary mirror, wait for the sync to
>> > complete, suspend i/o to get the disk consistent, then you can break
>> > the mirror and carry on. Terabytes :-) of data safely backed up in
>> > the space of seconds.

> No. Don't go there.  There's already a technology out there that does
> this correctly, called LVM snapshots.  And they let you resume normal
> operations after a very brief hesitation, and the snapshot holds the
> static image while you copy it off.

Will it let you put that snapshot on a hot-plug disk you can remove? For
my little system I'd quite happily mirror it off onto a hard-disk and
unplug it.

Oh - and I'm not running lvm. Not that I think there's anything wrong
with that, it's just yet another layer that I'm not (currently)
comfortable with.

Is there a sound technical reason not to go there, or is it simply a
case of "learn another tool for that job"? The less tools I have to know
the better, imho.

(Although why I'm worrying, I don't know. I know btrfs is planning to
make that obsolete :-)

Cheers,
Wol