I upgrade using YUM my CentOS 4 system the other night. I was noticing that X wasn't coming up because of a gdk_thread issue (actually, the window manager wasn't starting. I cold get X to start from the command line). Surprised that it took 587MB of downloads, since I was current as of September 29th. When rebooting, I was forced to the login prompt, because my LVM group with my home directory couldn't be mounted. I'm not very familiar with LVM, I had only used it to make one consolidated directory for my 100 and 160GB hard drives. Though lvmdisplay could show the volume group, fsck and mount didn't like it. Oh, and the upgrade didn't fix the thread problem. Anyone have an idea whether it was just me having the LVM problem? I'm currently reinstalling CentOS4 (pre update 1) from CD. At least when running diskdruid, I could mount the LVM group. So, after my install, assuming it is still visible when booting from hard drive, I'll backup those drives before running YUM again. I'f the window manager doesn't start up again, I'll reformat on my next install.