If you’re experiencing LVM snapshot problems, namely:

  LV system/rootsnap in use: not deactivating
  Couldn't deactivate new snapshot

It may be related to udev. In some kernel version (from what I’ve been reading here and there), there’s a race condition between udev (the thing that makes /dev tick) and LVM. LVM creates a snapshot volume, udev grabs it, LVM loses control. You can fix this by editing your udev rules under /etc/udev/rules.d (keep in mind this fix was made on Slackware 12):

1. Open /etc/udev/rules.d/50-udev.rules
2. Find the line with `LABEL=”persistent_input_end”` and after this line, add

3. KERNEL=="dm-[0-9]*",	OPTIONS+="ignore_device"

4. Restart

That should fix it. Please keep in mind this is for Slackware 12, and even still may not work. If you really want to solve all your problems, please download and use Slack 13 :).