raidframe panic

[Greg Troxel <gdt%ir.bbn.com@localhost>]

I have a machine with 2 x 400G SATA drives, which are too small, so I
bought 2 * 2T SATA drives as replacements.  I put one of the new ones in
an Aluratek docking station (== external drive case electrically, with
mechanicals for easy swapping), and then (netbsd-5, i386)

  created gpt label and RF partition

  created RAID1 set with this drive and a missing drive

  disklabeled the drive

  made filesystems, copied some data, etc.

Then, I

  unmounted the filesystems

  didn't do anything about the raid set

  powered off the drive

  waited about 10s

  did something like 'raidctl -s raid1', or 'disklabel raid1', and got a
  crash

It seems unplugging USB drives ought to be stable.  I realize raid is
tricky, because there's deconfiguring and there's failed.  But drive
going away from USB is pretty much failed, so this ought to be graceful.
Am I confused, or have I found a bug?

Separately, it seems like I should have done 'raidctl -u'.

Also, it would be nice if

  unmounted filesystems caused the raid set to be put in a state similar
  to unconfigured relative to clean/dirty status (it probably does)

  when a raid set's disks all go away, perhaps it should just vanish if
  it's autoconfigured, so plugging in two usb disks of a RAID1 set
  brings it back and it's just like a single disk.


But I think if the result was that raid1 showed as having the missing
disk as failed/missing and no panic, things would be much better.  



#0  0xc05e55c2 in cpu_reboot ()
#1  0xc0516890 in panic ()
#2  0xc05e8467 in trap ()
#3  0xc010ccb7 in calltrap ()
#4  0xc05e06a1 in db_read_bytes ()
#5  0xc01dabf7 in db_get_value ()
#6  0xc05e107d in db_stack_trace_print ()
#7  0xc0516865 in panic ()
#8  0xc05e8467 in trap ()
#9  0xc010ccb7 in calltrap ()
#10 0xc04acd8a in dkstrategy ()
#11 0xc050b289 in bdev_strategy ()
#12 0xc0204ca9 in rf_DispatchKernelIO ()
#13 0xc01fce91 in rf_DiskIOEnqueue ()
#14 0xc01fb17f in rf_DiskReadFuncForThreads ()
#15 0xc01ffdd9 in FireNode ()
#16 0xc01ffeed in FireNodeList ()
#17 0xc02003d0 in rf_FinishNode ()
#18 0xc01fae3d in rf_NullNodeFunc ()
#19 0xc01ffdd9 in FireNode ()
#20 0xc0200065 in rf_DispatchDAG ()
#21 0xc0214c27 in rf_State_ExecuteDAG ()
#22 0xc02155aa in rf_ContinueRaidAccess ()
#23 0xc01feffd in rf_DoAccess ()
#24 0xc0204fbe in raidstart ()
#25 0xc0200880 in rf_RaidIOThread ()
#26 0xc01002e1 in lwp_trampoline ()