Hello, I'm struggling to make a cloned CentOS 7 VM (under KVM) to work. The VM was cloned using mondorestore. Restore appears successful but the VM won't boot; see: http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-04.png I booted with CentOS 7 disk in troubleshooting mode (where the virtual disk was automatically mounted without issues) and I tried to repair: http://iweb.noa.gr/files/centos7/el7-rescue-scratchvm-20170502-01.png Also: # grub2-mkconfig -o /boot/grub2/grub.cfg ... /usr/sbin/grub2-probe: error: unknown filesystem. I then tried to repair using: https://sourceforge.net/p/boot-repair-cd/home/Home/ but it didn't manage to solve the problem. (It reported success but the VM still won't boot.) More interesting was the effort with the supergrub2 disk: http://www.supergrubdisk.org/super-grub2-disk/ This managed to identify the available "boot methods" and allowed me to boot correctly. See screenshots: http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-00.png http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-01.png http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-02.png Once I logged in, I checked /etc/fstab and /boot/grub2/grub.cfg but I didn't see any obvious problem. The are here as well: http://iweb.noa.gr/files/centos7/fstab http://iweb.noa.gr/files/centos7/grub.cfg However, I also followed these directions: https://www.techbrown.com/reinstall-grub2-boot-loader-centos-7-rhel-7.shtml to rebuild grub2.conf. The commands were completed successfully. Unfortunately, the OS still won't boot: same issue, see: http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-04.png I again tried to boot using the supergrub2 disk; this time the boot method detection produced the (slightly different) list you see in image: http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-05.png Using the supergrub2 disk I can boot and login successfully. Otherwise (i.e. directly) the box won't boot. As I know little about grub2 (and low-level linux) to troubleshoot the issue, can you please help identify and correct the problem? Why the VM always refuses to boot? Which is the reported device (on image -04) that remains unrecognized? I looked into /boot/grub/grub2.cfg but I didn't see any such UUID there. Where may it be referenced to be used during the boot process? Note: I never have such issues when restoring (using mondorestore) CentOS 5 or CentOS 6 mondoarchive backups (even on dissimilar virtual hardware). Can you please help me identify the problem, based on the above info, and make the VM normally bootable? Many thanks, Nick
On Wed, May 3, 2017 at 11:24 AM, Nikolaos Milas <nmilas at noa.gr> wrote:> > Hello, > > I'm struggling to make a cloned CentOS 7 VM (under KVM) to work. > > The VM was cloned using mondorestore. Restore appears successful but the VM won't boot; see: > > http://iweb.noa.gr/files/centos7/supergrub2-scratchvm-20170503-04.pngDoes the UUID of root filesystem in /etc/fstab match the actual UUID as reported by blkid? And remove /etc/lvm/cache/.cache if it exists Marcelo "?No ser? acaso que esta vida moderna est? teniendo m?s de moderna que de vida?" (Mafalda)
On 3/5/2017 10:41 ??, Marcelo Roccasalva wrote:> Does the UUID of root filesystem in /etc/fstab match the actual UUID > as reported by blkid? And remove/etc/lvm/cache/.cache if it existsThank you Marcelo for replying, The directory /etc/lvm/cache/ is empty. And, yes, the UUID matches: # blkid /dev/vda1: UUID="297e2939-d6f5-431a-9813-9848368ee306" TYPE="xfs" /dev/vda2: UUID="OR1eUA-1hhb-PCff-qybQ-rLt4-JuTN-EcWX61" TYPE="LVM2_member" /dev/sr0: UUID="2017-03-16-21-15-06-00" LABEL="ISOIMAGE" TYPE="iso9660" PTTYPE="PMBR" /dev/mapper/centos-root: UUID="fcee6215-e97a-4a4f-9473-5115f8559683" TYPE="xfs" /dev/mapper/centos-swap: UUID="b220b45f-ae22-4393-a74d-90b03d37c41b" TYPE="swap" # cat /etc/fstab # # /etc/fstab # Created by anaconda on Thu Dec 8 13:40:06 2016 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/centos-root / xfs defaults 0 0 UUID=297e2939-d6f5-431a-9813-9848368ee306 /boot xfs defaults 0 0 /dev/mapper/centos-swap swap swap defaults 0 0 10.201.40.34:/data/col1/noc-bkups-1 /mnt/dd2500-1 nfs auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 0 0 Any other ideas? Thanks, Nick
On 3/5/2017 5:24 ??, Nikolaos Milas wrote:> Using the supergrub2 disk I can boot and login successfully. Otherwise > (i.e. directly) the box won't boot.In the meantime, I also tried rescatux (https://sourceforge.net/projects/rescatux/) repair disk; it failed as well. The situation remains the same. How can we fix this cloned CentOS 7 installation to become bootable? Please advise! Thanks, Nick