rpm from rescue CD

[Bob Tennent <rdtennent hotmail com>]

I'm trying to use rpm from the 1st install CD of FC4. I'm trying to
re-install glibc packages that didn't get installed properly leaving the
system without ld. I've tried the following:

  rpm -U --replacepkgs --root /mnt/sysimage glibc*

and am getting

  error: can't create transaction lock on /var/lib/rpm/_db.000

I've tried adding --dbpath /mnt/sysimage/var/lib/rpm but rpm isn't
recognizing that option.  What should I do?

Bob T.