Using the standard upgrade proceedures, Debian Etch + LVM will fail to upgrade to Debian Lenny gracefully. This is due to the kernel modules and is simple to avoid.
Before changing apt sources (They should be etch)
apt-get update
apt-get upgrade
reboot if kernel upgrades
Now change your apt sources (Lenny or Stable)
apt-get update
apt-get upgrade
NOTE: At this point lvm2 is [...]
There appears to be a bug in Debian’s key signing system. Depending on your apt sources you may run in to packages signed by a key that Debian doesn’t like. Annoyingly, these are Debian-signed packages, but unless you want to fix it, here is a workaround.
http://non-us.debian.org is a repository signed with F1D53D8C4F368D5D, but [...]
There are a million pages devoted to initramfs so I won’t go in to what it is, but if you have a Dell 1655 or other machine with serial-attached-SCSI and use Debian or a Debian-derived Linux distribution such as Ubuntu or Kbuntu, you may have run in to an issue booting after installing a kernel [...]