Comment 0 for bug 1423796

I'm experiencing with Vivid Vervet on a virtual machine and tried a new LVM feature, lvmcache. I made a cache for the root file system, rebuilt the initrd and rebooted the VM.

At boot time, the system failed to activate the root LV. After some investigation, I found out, it's because the initrd is missing some essential stuff needed for activating a cached LV.

The initrd was missing the dm-cache module. I regenerated the initrd with explicitly listing dm-cache in /etc/initramfs-tools/modules, but the system still can't boot up, because now it is missing the /usr/sbin/cache_check utility.

As SSDs are becoming more and more common, I think it will be common to use them as cache for root file systems, thus it is mandatory to make sure that an initrd can mount an lvmcached root device when necessary, preferably without /etc/initramfs-tools/modules and other initrd hacking.