Re: How does one resize/expand a softraid RAID1?

> On 14 Jul 2026, at 05:21, Stuart Henderson <[email protected]> =
wrote:
>=20
> On 2026-07-13, Chris Ross <[email protected]> wrote:
>> [a failed disk ; softraid mirror ; docs for bioctl ; OpenBSD]
>>=20
>> Is there a way to replace a failed drive with a larger one, rebuild =
the
>> mirror onto it, then replace the smaller remaining drive with one of =
equal
>> size and rebuild onto that?  [=E2=80=A6]
>>=20
>=20
> Not supported with softraid. You can't create a "1-disk RAID1" and add
> the second drive later either. Unless you want to get dirty with =
poking
> at low level data structures, you'll either need to have both new =
drives
> and the remaining working old drive connected at the same time and
> dump/restore, or dump to external media + swap drives + restore, etc.

That=E2=80=99s a shame.  Would it be particularly difficult inside of =
softraid to
get to the equivalent of ZFS=E2=80=99 autoexpand behavior?  It seems =
like it
shouldn=E2=80=99t be to tell the softraid device to just understand that =
it=E2=80=99s the
size of the smallest member of the mirror.  At least for RAID1 it =
shouldn=E2=80=99t
be more complicated than that.  Then, what the FS layer does underneath
that is a separate issue, but mostly a solved problem for FFS already.

I don=E2=80=99t have enough bays in this system to build a whole other =
RAID1
and copy the data, so I=E2=80=99ll have to take it offline for a while =
and move
data around the network.  In this case, I=E2=80=99m looking at less than =
a TB
so it won=E2=80=99t be a problem, but it would be if there were lots of =
data.

Thanks for the answers all.

-Chris=