[rescue] Drive Replacement Question

[Brian Deloria]

I've got a drive I need to replace in a V240, c1t1d0 which is a root
mirror.  metastat still reports it as being ok, but I am debating whether to
power the machine off and replace the disk, go through the process of
booting the root device with less than 50% of the metainfo slices intact and
just do a metareplace on it, or to delete the metadb off of the problem
drive while the machine is still up in single user mode and hotswap the
device with the machine still on.

Most of the documentation that I've found simply refers to replacing the
drive after it has failed completely, or to move the metainfo over to
another slice/drive/add a new drive none of these are possible based on the
configuration by my predecessor.  The situation that I'm in however doesn't
quite fit into that and I was wondering if one way was riskier than the
other or preffered.  Taking the machine offline in off hours is acceptible
so I don't neccessarily need to do this hot.

Thanks,

Brian