[SOLVED] VM only boots from USB key, but not from identical lvm-thin logical volume connected with virt-io or sata

[Andreas S.]

Hi Proxmoxians,

I have created a Linux VM based on HiveOS (which is based on Ubuntu 16.04). The installer image is meant to written to a USB key, which I have done. I passed the USB key to the VM and it's booting and working fine.

Of course I don't want to use the USB key forever now. Hence, I created (first with virt-io scsi, second with SATA) a thin-lvm volume to copy over the content of the USB key. \[The documentation describes exactly to this\]([https://hiveos.farm/guides-hdd\_move/](https://hiveos.farm/guides-hdd_move/)), which I have done for my Proxmox host: `dd if=/dev/sdd bs=4M of=/dev/mapper/pve-vm--100--disk--0 count=2560` (The USB key's partition is 7G, the target volume 10G, the count is one below the last try which ended with target full error).

This are the relevant disks:
```
# EFI partition
Disk /dev/mapper/pve-vm--100--disk--1: 4 MiB, 4194304 bytes, 8192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes

GPT PMBR size mismatch (14745599 != 61439999) will be corrected by write.

# the USB key
Disk /dev/sdd: 29.3 GiB, 31457280000 bytes, 61440000 sectors
Disk model: USB Stick 32 GB
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 75EC96FF-FEA6-4E82-8270-2359AA33BF56

Device Start End Sectors Size Type
/dev/sdd1 2048 43007 40960 20M Microsoft basic data
/dev/sdd2 43008 45055 2048 1M BIOS boot
/dev/sdd3 45056 126975 81920 40M EFI System
/dev/sdd4 126976 14745566 14618591 7G Linux filesystem

# the targe thin-lvm volume, which I want to boot from
Disk /dev/mapper/pve-vm--100--disk--0: 10 GiB, 10737418240 bytes, 20971520 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
```

And the PVE qemu config `/etc/pve/qemu-server/100.conf`:
```
agent: 1
balloon: 512
bios: ovmf
boot: order=sata0
cores: 2
efidisk0: local-lvm:vm-100-disk-1,size=4M
hostpci0: 09:00,pcie=1
machine: q35
memory: 2048
name: orca-hiveos
net0: e1000=BE:1D:14:1B:25:C9,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
sata0: local-lvm:vm-100-disk-0,discard=on,size=10G
scsihw: virtio-scsi-pci
smbios1: uuid=802e3aa8-0905-47e6-b3f5-7e723194c42d
sockets: 1
vga: qxl
vmgenid: 697d4e00-fa69-47cf-a3e7-9b4a1cd9a70e
```

When I boot, then I reach the Grub boot menu. Then I get a blank screen with a cursor, where it stops. It's running Proxmox 6.4, which is a clean install from two days ago.

I am running out of ideas. Any idea what I could try?

 

[Andreas S.]

I got an pointer from somebody else. Just to document what had been the reason and how it finally worked:

Inspecting the partition tables from within the VM turned out: the thin-lvm clone had been missing some partitions. Really don't understand why though. ¯\_(ツ)_/¯

I opened fdisk for the USB key, wrote out the partition table with O.

Then I opened thin-lvm partition with fdisk and also wrote out the partition table with O.

Copied over the partition lines from the USB key file into the other one. Opened the thin-lvm partition again with fdisk and loaded the partition table file with I. Wrote it to the partition with w. Now I had the same partitions on the thin-lvm partition.

Finally copying over every single partition with dd. I found grub had been configured with the OS partition's UUID. This had been copied as well. Hence, nothing more to do than to reboot.

Now it works.