When attempting to start up my 5th DomU, I run into an error:

[root@minerva ~]$ xm create -c /usr/pkg/etc/xen/domU.www
Using config file "/usr/pkg/etc/xen/domU.www".
Error: Adding extent to vbd failed: device (vbd (uname file:/virtual/www.img) (dev wd0d) (mode w)), error 8

[root@minerva ~]$ tail -1 /var/log/messages
Jun 22 17:02:41 minerva /netbsd: xbdback VBD grow domain 14: unknwon device 0x2c890

(yes, "unknown" has a spelling mistake in the log)

To create the DomU, I merely copied my standard NetBSD image file to a
new file (all the DomUs run a version of the  same image file though
each is customized for IP address, etc) and created a new config file:

kernel = "/netbsd-XENU"
memory = 64
name = "www"
cpu = -1
nics = 0
disk = [ 'file:/virtual/www.img,wd0d,w' ]
root = "/dev/wd0d"

/virtual/www.img exists and has the same md5 as my original "barebones"
image file.

It almost seems like I've run out of virtual devices, but it looks to me
like there's 64 of them in /dev.

Any pointers on where I should look to troubleshoot this?

-T


-- 
"Any intelligent fool can make things bigger, more complex, and more
 violent. It takes a touch of genius -- and a lot of courage -- to move
 in the opposite direction."
    -- Albert Einstein