[j-nsp] EX dual-root partitioning snapshots

[Chuck Anderson]

With 10.4R3 and newer dual-root partitioning feature, on initial
upgrade most of my EX switches formatted & upgraded both the primary
and alternate root slices correctly.  However, subsequent upgrades
don't appear to keep those in sync and you need to do:

request system snapshot media internal slice alternate

to update the backup copy.  However, there doesn't appear to be a way
to do this for all members of a virtual chassis.  Instead you have to
do each one individually:

request system snapshot media internal slice alternate member 0
request system snapshot media internal slice alternate member 1
request system snapshot media internal slice alternate member 2
request system snapshot media internal slice alternate member 3
request system snapshot media internal slice alternate member 4
request system snapshot media internal slice alternate member 5
request system snapshot media internal slice alternate member 6
request system snapshot media internal slice alternate member 7
request system snapshot media internal slice alternate member 8
request system snapshot media internal slice alternate member 9

Additionally, some of my switches ended up with /dev/da0s1a as the
primary, /dev/da0s2a as the backup, but others are reversed.  Worse
still, I have some VC's where the members are mixed, some slice 1,
others slice 2 as primary.  What a pain.

Are there some tricks I'm missing for how to keep the versions and
primary/backup slices in sync across an entire VC?  Is there any way
to change which slice is considered "primary" and which "backup" so I
can at least fix all the members of the VC to be the same?

Thanks.