Thank you for the quick response.

> Strange way to do this, as libguestfs can do all this.

Sorry to ask this (I'm a newly graduated engineer and I new to the virtualization world), but how can libguestfs do all of the above?, do you mean it can create all the partitions inside a new lvm volume or a new raw image??

> Did you copy the syslinux.cfg file into the guest? The error message
> you reported sounds like extlinux is installed but cannot read its
> config file.

Yes I'm sure that I copied the syslinux.cfg in the guest and that's why I was confused with the error message.

My problem is that the exact same steps worked on a ubuntu 14.04 host with libguestfs 1.24.5 , and I can't see why it won't work on a centos7 host , that's why I thought about a problem with this libguestfs version (1.30.3).

Here's how I installed extlinux (I already saw the link that you sent me and I don't think I made a mistake) but the guest still don't want to boot:

[root@localhost libguestfs-1.30.3]# ./run guestfish -i -a /dev/vm_volumes/clone2

Welcome to guestfish, the guest filesystem shell for

editing virtual machine filesystems and disk images.

Type: 'help' for help on commands

'man' to read the manual

'quit' to quit the shell

Operating system: CentOS Linux release 7.1.1503 (Core)

/dev/sda1 mounted on /

><fs> ls /boot/

.vmlinuz-3.10.0-229.el7.x86_64.hmac

System.map-3.10.0-229.el7.x86_64

config-3.10.0-229.el7.x86_64

grub

grub2

initramfs-0-rescue-c898899928d341b58ae4d02802d19340.img

initramfs-3.10.0-229.el7.x86_64.img

initramfs-3.10.0-229.el7.x86_64kdump.img

initrd-plymouth.img

ldlinux.sys

mbr.bin

symvers-3.10.0-229.el7.x86_64.gz

syslinux.cfg

vmlinuz-0-rescue-c898899928d341b58ae4d02802d19340

vmlinuz-3.10.0-229.el7.x86_64

><fs> cat /boot/syslinux.cfg

DEFAULT linux

LABEL linux

SAY Booting the kernel

KERNEL /boot/vmlinuz-3.10.0-229.el7.x86_64

INITRD /boot/initramfs-3.10.0-229.el7.x86_64.img

APPEND ro root=UUID=8e137cd9-cd6c-4205-a27f-211d6184a5f3

><fs> copy-file-to-device /boot/mbr.bin /dev/sda size:440

><fs> extlinux /boot

><fs> part-set-bootable /dev/sda 1 true

Thank you for your time and understanding.