zfs drive replacement issues

[Todd Wasson]

> I'm not certain that you really always want to do that. When you offline a
> device in a redundant pool you lose that redundancy. If you have a drive
> that is completely dead, it is obviously the right thing to do, but
> otherwise perhaps not. Were you the have another failure during the
> rebuild, or if there was another error on a different vdev, you wouldn't
> be able to recover that data because of the missing device. The same
> reason why offlining and replacing each device in a raidz1 to "grow" it
> isn't as safe as you might think -- any error could lead to data loss.
>
> Just food for thought.

I'm guessing the implication here is that it's better to connect the new drive 
in addition to the old one, then, like via USB or eSATA interface?  In a machine 
with no extra interfaces, as was the case for me, offlining it seemed to be the 
only choice.  Maybe it's just time to invest in a USB SATA cable, just in case...

Thanks!


Todd