So I was building some installation floppies on the i386 last night, at
the same time I was building a kernel and compiling another package (in
other words, lots of disk I/O was happening).  This was with a fairly
current -current (May 20th, I think).

Shortly into the part where it started building the vnd image, my two
builds and the process doing I/O on the vnd hung.  The wait channel didn't
have a name associated with it (it was just a hex address).  I could do
_some_ I/O with other processes, but occasionally they would hang.  All
the processes that hung had the same address for the wait channel.

When I rebooted the machine, it hung at the "syncing disks..." message.

I repeated this a couple of times -- same thing each time.

I could build install floppies fine if I wasn't doing the two compiles.

I know this is a rather vague problem report -- I'm curious if anyone
else had encountered similar problems before I tried to debug it.

--Ken