On 17/01/2022 17:59, Jaromír Cápík wrote:

Few times a year, different reasons. Usually requests for higher capacity
where I need to replace all drives one by one and then grow the array.
Sometimes reallocated sectors appear in the SMART output and I never
let such drives in the array considering them unreliable. The --replace
feature is nice, but often there's no room for one more drive in the
chasis and going that way requires an external USB3 rack and a bit of
magic if the operation cannot be done offline.

You seen the stuff about running raid over USB? Very unwise?

Do you have room for an eSATA card? If so, get an external SATA cage, 
and you can swap a drive out into the cage, rebuild the array with 
--replace, and repeat. Much safer, probably much quicker, and no extra 
work shutting down the system to replace each drive in turn. And if your 
chassis is hot-swap, then all the better, no downtime at all. Just a few 
moments danger each time you physically swap a drive.

So, I still hope someone will find enough courage one day to implement
the new optional sync strategy:)

There is the argument that increasing the load on the drive increases 
the risk to the drive ...

Cheers,
Wol