On 10/19/2015 07:07 PM, Karl E. Jorgensen wrote: > Hi > > On Mon, 2015-10-19 at 18:24 +0300, Ivan Boro wrote: >> Looks like subj. >> Have a KVM machine with jessie assembled via debootstrap. Fstab states >> >> /dev/vda2 / ext4 rw 0 0 >> >> The partition labeled vda2 is listed in grub.cfg as the root partition >> by its uuid.(via update-grub) >> >> Added a disk to have swap on it. Booted normally, despite the fact, that >> the new swap-disk was automatically labeled as vda and the disk with >> root is as vdb: >> >> # mount | grep ' / ' >> /dev/vdb2 on / type ext4 (rw,relatime,data=ordered) >> >> No errors or warnings in dmesg. >> >> So, systemd mounted root partition, whitout looking into fstab. >> >> I don't have much experience in systemd, and now wonder how this "smart" >> mount works. > > Well - I doubt this is systemd specific. > > /etc/fstab is in the root file system. Thus, the system can only > examine /etc/fstab _after_ the root file system has been mounted... > > Instead you may want to examine the kernel command line (e.g. in grub > or /proc/cmdline) - it should have "root=xxxx" in it. Nowadays that is > often specified via a UUID - and the UUID stays the same if if you move > disks about. > > Hope this helps >
Yes. Fun thing, I've accidentally put /dev/vda1 to my host's filesystem's fstab, and the host system runs init as pid=0. Everything boots normally. Now I doubt, is the root entry present in the fstab file generated automatically during system setup.
