When I did a remote geographic disk based mirroring product a few years ago, I just had an ioctl that said that this disk was special for a while. Then the open routine would fail. This flag was cleared in the close routine (and by the companion ioctl). I did allow users to open the device w/o read and write to get status on the device, but that was it until the rebuilding process was complete. Granted, this was the control device for the mirroring driver... But that worked fairly well.
I only needed to do this in recovery situations for a few hundred disk I/Os, so the average user would likely have never noticed. Oh, this was on Solaris, but the concepts are exactly the same for FreeBSD. Warner To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message
