Adding a new hard drive to LVM

[Derek Scollon]

I'm running FC3 and currently have one 300GB SATA drive which looks like this.

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                     286285288 239994144  31748708  89% /
/dev/sda1               101086     33733     62134  36% /boot
none                    517796         0    517796   0% /dev/shm

 I've added a second drive today and am following the instructions here...

http://www.hants.lug.org.uk/cgi-bin/wiki.pl?action=browse&id=LinuxHints/LogicalVolumeManagement&oldid=LogicalVolumeManagement (section titled "Adding another disk")

...to add this drive to the volume group. I've successfully got as far as step 5 and hit a problem, since trying to unmount that volume group tells me that / is in use. Trying step 6 warns me that running e2fsck on a mounted filesystem can cause severe damage, at which point I chicken out. Is it safe to skip to step 7 and run resize2fs without unmounting the filesystem first or should I be doing something different?

-- 
Best regards,
Derek