Boot failed: not a bootable disk

Hi everyone,

This post is similar to and
These forum post are unresolved.

I have a VM running Linux Centos 6.7, 64-bit. 4GB RAM, and only a 32GB of disk. The mainly usage is to relay internal mails to Internet , using Sendmail-SMTP.
Yesterday was installed some antispam protections (MailScanner from Apparently the installation process intensively writes the hard disk with multiple small files. Once installed, there is approximately 500 mb more in the file system.

I restarted the virtual machine to make sure the service was installed correctly. But when restarting, the machine presented the error "Boot failed: not a bootable disk"

I remember that in previous versions of Proxmox there were tools to analyze qemu images. But currently in this Proxmox 5.2-1, how to identify the type of file - if it is qemu or if it is another format? And with what tools can it be repaired?


Proxmox Staff Member
Staff member
Oct 1, 2014

for image manipulation, you can use "qemu-img"
the check operation will check the consistency of the image.

Use as Disk bus only virtio and SCSI with virtio controller.
All other buses can make problems.
Hi Wolfgang, thanks for your reply

When I´m intended to run qemu-img: "qemu-img check vm-306-disk-1" have received the reply: "qemu-img: This image format does not support checks"

Path: /dev/zvol/rpool/data

Config file:
boot: c
bootdisk: sata0
cores: 1
memory: 512
name: 15.1-Correos
net0: e1000=6E:B2:BB:27:34:93,bridge=vmbr0,link_down=1
numa: 0
onboot: 1
ostype: l26
scsi0: local-zfs:vm-306-disk-1,size=32G
sockets: 1

I have tried with SCSI/VIRTIO disk, with the same negative result.


Proxmox Staff Member
Staff member
Oct 1, 2014
ZFS need not be check because zfs can't corrupt on mage level.

Your problem is your VM use the wrong boot dev.
Please the correct boot dev in the options tab.
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Hi again Wolfgang,
The machine are working previously without a problem, for a couple of years, in the same physical server.
When I finished updating the packages and restarted the virtual machine, I found the error mentioned. As I said before, it is not a bus or connector problem, since nothing was modified externally: the machine was working.


New Member
Mar 10, 2019
I’ve got similar issue, my pfSense vm has been working fine for quite a long time and now it won’t boot after I’ve removed it and restored it from backup.
A few months ago, about this post:
Maybe your backup is corrupt?
The backup files are correct. I just restored some of the backup files, and I can boot ok.
But... some weeks later... the same problem again.. Restarted the VM ,, and find Boot failed: not a bootable disk.

Have some tool for test the image in ZFS, or how I can recover the ZFS image to mount in another filesystem like EXT3-EXT4, to recover the data in the image?



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