Restoring root fileset on 4.0d

Hello Managers,
This is something I have done successfully before but for some reason 
it is failing today.

I want to restore the root advfs filesystem on a 4.0d system. I did 
this successfully on the same system last month, however, when I did 
it last month, I mistakenly named the root advfs fileset "roottmp" 
with advfs domain "root_domain" (don't ask how I did such a thing. 
Just accept that I did it...). Surprisingly it works even with that 
fileset name. However, the backups fail  because the routine tries to 
create a clone of "root_domain#root" which doesn't exist. Also, I 
know that the wrong fileset name will cause me further headaches 
ahead. So even though the system is functional, I wanted to make it right.

I tried today to restore from another tape vdump and I am getting the 
problem I will show below. Unfortunately, I am not at the site where 
the restore was taking place and was working with someone who was 
only my hands-on, so I don't have all the exact error messages.

Here is the procedure I was following:

1) Booting from the 4.0g CD ( the version we are running is 4.0d but 
this is the only CD they have on the site. It worked last month)
2) Upon starting X, a message is displayed warning that this version 
of the operating system has different disk partition size 
requirements. We click OKAY.
3) It opens the Installation Window displaying things like SETUP 
DONE, VIEW SOFTWARE, etc. We are selecting UNIX SHELL.
4) At the UNIX shell, we cd to /dev and MAKEDEV rz8  (the current 
system disk and the one we want to restore to) and MAKEDEV tz21 (the 
tape device). Both commands successfully create the device files.
5) I can read the disklabel of rz8 and have even successfully 
re-written the disk label with the -R option. So I feel comfortable 
that the disk is accessible and the device files were created.
6) We try to create the root domain on /dev/rz8a with 
"mkfdmn  /dev/rz8a root_domain". This fails with the following message:

/dev/rrz8a is an invalid device or cannot be opened
The disklabel for /dev/rrz8a cannot be updated
Quitting
Mkfdmn:  can't create new domain 'root_domain'

7) We have tried cd'ing in and out of /dev and /var and /.
8) We have tried various switches in mkdfmn like -o and -r. We have 
tried using the raw device /dev/rrz8a.
9) We have tried reading the current disklabel and re-writing with 
disklabel -Rrt advfs rz8 <file? boot.advfs  which succeeds but does 
not solve the mkdfmn problem.


Does anyone have any ideas?
This is really bizarre since I did the same procedure last month 
successfully. The only difference was that last month, the disk we 
were restoring to was a replacement disk with no operating system on it.

It looks like something has opened the rz8a partition (since it is 
obviously a valid device) but I don't know how to determine what 
process has it opened.

Any help would be appreciated. I am at a lost here.

Thanks in advance.
John