Re: RAIDframe: reducing a three-component RAID 1 to two

["Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost>]

On Thu, Mar 13, 2025 at 06:58:00PM +0100, Edgar Fuß wrote:
> So I happily configured several RAIDframe level 1 RAIDs with three components 
> and just learned this is unsupported. How do I reduce them to two components 
> without losing the data?

Find the two components with matching modification counter and use just
those?  Not sure off hand how to print out a raid(4) component label;
the modification counter is the third 32-bit quantity in the component
label (at byte 12-15), just after the 32-bit quantity that's the array
serial number.  If there aren't two (or more) components with matching
modification counters you'd want to start with only the component with
the highest modification counter.