When adding or replacing a vdev with a different sector size the
error message should be more useful. In addition to describing
the problem provide a hint that the '-o ashift' option can be
used to override the optimal default value.
Since using a non-optimal value may incur a significant performance
penalty we should issue this error. But there a numerous reasons
why a administrator may wish to do this anyway.
Signed-off-by: Niklas Edmundsson <ZNikke@github>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2421
d4aae2a054