For testing purposes I have two identical VMs except that one is i386
and the other amd64. They share the same tap(4) interface, so they
cannot run at the same time:
$ vmctl status
ID PID VCPUS MAXMEM CURMEM TTY OWNER NAME
1 35130 1 128M 102M ttyp6 mpi amd64
10 - 1 128M - - mpi i386
Since I make a lot of mistakes, it generally happens that I start one
of the two while the other is running. When this happens vmctl(8) tells
me the following:
$ vmctl start i386 -c
vmctl: start vm command failed: Device busy
I believe that EBUSY comes from the fact that tap0 is already in use.
However after this error my VM has disappeared and I cannot start it
without running "# vmctl reload":
$ vmctl status
ID PID VCPUS MAXMEM CURMEM TTY OWNER NAME
1 35130 1 128M 102M ttyp6 mpi amd64
As non-privileged user this is annoying because I need to be root to
do a "reload".