Dne 19. 11. 24 v 3:11 "Thomas Brücker" napsal(a):
Dear Mr. Kabelac,
I have (at first) not been aware, that at the end of your mail, you asked
me probably 'about pseudo-raid'. It is difficult for me to give you an
abstract definition of it, so I give you an example:
Hi
Hmm I'm not even sure I want to know here more details about this construct :)
but why don't you just simply create 'regular' raid4 LV where those legs are
located on the same storage device/PV ?
It's certainly not a 'default' nor 'suggested' way of using raid, however
with 'lvcreate --alloc anywhere' you can certainly create any sort of mapping
without doing those very strange dmsetup mapping yourself.
And while I can 'see' a small value in having the same data stored multiple
times on the same drive - the protection you get from this is close to nothing
- especially with NVMe/SSD - where they in the most cases collapse in a
'total' way - so you simply have no access to drive at all. However what you
get for 100% is a major drop of your storage performance.
With prices of storage these days I'd simply recommend to simply use the raid
the way it's supposed to be used.
Regards
Zdenek
