FC 15 dosn't boot after fdisk

[Tohes]

Hi.
I have some problem with FC 15.
I installed FC 15. I use disk splitting by default:
#df
rootfs 3676792 2143240 1346776 62% /
udev 503976 0 503976 0% /dev
tmpfs 511112 0 511112 0% /dev/shm
tmpfs 511112 544 510568 1% /run
/dev/mapper/vg_fedora-lv_root
3676792 2143240 1346776 62% /
tmpfs 511112 0 511112 0% /sys/fs/cgroup
tmpfs 511112 0 511112 0% /media
/dev/sda1 495844 31566 438678 7% /boot

The problem is in the following:
i type:
#fdisk /dev/sda1
v
w
I reboot FC. FC drop in dracut.
FC boot only after i type:
dracut:/# lvm vgchange -ay
dracut:/# exit

How can i fix it?
P.S
I tried this twice on my test server.
P.P.S
Thanks for help. Sorry for my bad English.

[george_toolan]

What exactly is the error message? Try

       --ignorelockingfailure
              This lets you proceed with read-only metadata operations such as
              lvchange  -ay and vgchange -ay even if the locking module fails.
              One use for this is in a system init script if the  lock  direc‐
              tory is mounted read-only when the script runs.

[Tohes]

Error message is the following:
Dropping to debug shell
sh: can't access tty; job control turned off

In which script must i add --ignorelockingfailure?

It is necessary, that the FC was loaded automatically.

P.S
I use Fedora 15