The reason for this is that SERIAL is a made up name. It’s not the actual
serial of a device. The SERIAL_SHORT is the actual serial name.

I think MAAS already creates serial for the devices it creates, I would
have to check, but I don’t think we can rely on using SERIAL because it’s
jot the actual serial of the disk, it is again, just a made up name
assigned from the software perspective.



On Sat, Dec 8, 2018 at 10:35 AM Dmitrii Shcherbakov <
<email address hidden>> wrote:

> ** Description changed:
>
>   Created a domain with a number of different devices (virtio-blk, virtio-
>   scsi, sata, NVMe) and added <serial/> tag to all of them for testing of
>   lp:1735839. Querying udev, I can see that ID_SERIAL is set but MAAS does
>   not use it to populate the "serial" field during commissioning.
> +
> + The reason is that only ID_SERIAL_SHORT is collected by MAAS, not
> + ID_SERIAL.
>
>   https://paste.ubuntu.com/p/pM7Tx8Hgbw/
>
>       <disk type='file' device='disk'>
>         <driver name='qemu' type='qcow2'/>
>         <source file='/mnt/sec1/libvirt-images/maas-vhost6-virtio0.qcow2'/>
>         <backingStore/>
>         <target dev='vda' bus='virtio'/>
>         <serial>disk2</serial>
>         <alias name='virtio-disk0'/>
>         <address type='pci' domain='0x0000' bus='0x06' slot='0x00'
> function='0x0'/>
>       </disk>
>       <disk type='file' device='disk'>
>         <driver name='qemu' type='qcow2'/>
>         <source file='/mnt/sec1/libvirt-images/maas-vhost6-virtio1.qcow2'/>
>         <backingStore/>
>         <target dev='vdb' bus='virtio'/>
>         <serial>disk3</serial>
>         <alias name='virtio-disk1'/>
>         <address type='pci' domain='0x0000' bus='0x07' slot='0x00'
> function='0x0'/>
>       </disk>
>
>   ubuntu@maas-vhost6:~$ udevadm info --query=property --name /dev/vda |
> grep ID_SERIAL
>   ID_SERIAL=disk2
>
>   ubuntu@maas-vhost6:~$ udevadm info --query=property --name /dev/vdb |
> grep ID_SERIAL
>   ID_SERIAL=disk3
>
>   Looking at the full output I can see that in the udev output there is no
>   ID_SERIAL_SHORT for virtio devices:
>
>   udevadm info --query=property --name /dev/vda
>   DEVLINKS=/dev/disk/by-path/virtio-pci-0000:06:00.0
> /dev/disk/by-dname/vda /dev/disk/by-path/pci-0000:06:00.0
> /dev/disk/by-id/virtio-disk2
>   DEVNAME=/dev/vda
>   DEVPATH=/devices/pci0000:00/0000:00:02.5/0000:06:00.0/virtio5/block/vda
>   DEVTYPE=disk
>   ID_PATH=pci-0000:06:00.0
>   ID_PATH_TAG=pci-0000_06_00_0
>   ID_SERIAL=disk2
>   MAJOR=252
>   MINOR=0
>   SUBSYSTEM=block
>   TAGS=:systemd:
>   USEC_INITIALIZED=1789047
>
>   And ID_SERIAL_SHORT is something that MAAS collects in provisioning
>   scripts for block devices:
>
>
> https://github.com/maas/maas/blob/2.5.0-rc2/src/provisioningserver/refresh/node_info_scripts.py#L513-L521
>       # Grab the device path, serial number, and sata connection.
>       UDEV_MAPPINGS = {
>           "DEVNAME": "PATH",
>           "DEVPATH": "DEVPATH",
>           "ID_SERIAL_SHORT": "SERIAL",
>
>   As a result the serial field is empty for virtio devices (noticed first
>   by looking at the UI):
>
>   https://paste.ubuntu.com/p/RzMk7r5ZGH/
>
>           {
>               "firmware_version": null,
>               "name": "vda",
>               "filesystem": null,
>               "id_path": "/dev/vda",
>               "block_size": 2048,
>               "system_id": "xeqrrw",
>   # ...
>               "path": "/dev/disk/by-dname/vda",
>   # ...
>               "serial": "",
>
> ** Description changed:
>
>   Created a domain with a number of different devices (virtio-blk, virtio-
>   scsi, sata, NVMe) and added <serial/> tag to all of them for testing of
>   lp:1735839. Querying udev, I can see that ID_SERIAL is set but MAAS does
>   not use it to populate the "serial" field during commissioning.
>
>   The reason is that only ID_SERIAL_SHORT is collected by MAAS, not
> - ID_SERIAL.
> + ID_SERIAL and it is not present for virtio-blk devices (even if it is
> + provided via QEMU).
>
>   https://paste.ubuntu.com/p/pM7Tx8Hgbw/
>
>       <disk type='file' device='disk'>
>         <driver name='qemu' type='qcow2'/>
>         <source file='/mnt/sec1/libvirt-images/maas-vhost6-virtio0.qcow2'/>
>         <backingStore/>
>         <target dev='vda' bus='virtio'/>
>         <serial>disk2</serial>
>         <alias name='virtio-disk0'/>
>         <address type='pci' domain='0x0000' bus='0x06' slot='0x00'
> function='0x0'/>
>       </disk>
>       <disk type='file' device='disk'>
>         <driver name='qemu' type='qcow2'/>
>         <source file='/mnt/sec1/libvirt-images/maas-vhost6-virtio1.qcow2'/>
>         <backingStore/>
>         <target dev='vdb' bus='virtio'/>
>         <serial>disk3</serial>
>         <alias name='virtio-disk1'/>
>         <address type='pci' domain='0x0000' bus='0x07' slot='0x00'
> function='0x0'/>
>       </disk>
>
>   ubuntu@maas-vhost6:~$ udevadm info --query=property --name /dev/vda |
> grep ID_SERIAL
>   ID_SERIAL=disk2
>
>   ubuntu@maas-vhost6:~$ udevadm info --query=property --name /dev/vdb |
> grep ID_SERIAL
>   ID_SERIAL=disk3
>
>   Looking at the full output I can see that in the udev output there is no
>   ID_SERIAL_SHORT for virtio devices:
>
>   udevadm info --query=property --name /dev/vda
>   DEVLINKS=/dev/disk/by-path/virtio-pci-0000:06:00.0
> /dev/disk/by-dname/vda /dev/disk/by-path/pci-0000:06:00.0
> /dev/disk/by-id/virtio-disk2
>   DEVNAME=/dev/vda
>   DEVPATH=/devices/pci0000:00/0000:00:02.5/0000:06:00.0/virtio5/block/vda
>   DEVTYPE=disk
>   ID_PATH=pci-0000:06:00.0
>   ID_PATH_TAG=pci-0000_06_00_0
>   ID_SERIAL=disk2
>   MAJOR=252
>   MINOR=0
>   SUBSYSTEM=block
>   TAGS=:systemd:
>   USEC_INITIALIZED=1789047
>
>   And ID_SERIAL_SHORT is something that MAAS collects in provisioning
>   scripts for block devices:
>
>
> https://github.com/maas/maas/blob/2.5.0-rc2/src/provisioningserver/refresh/node_info_scripts.py#L513-L521
>       # Grab the device path, serial number, and sata connection.
>       UDEV_MAPPINGS = {
>           "DEVNAME": "PATH",
>           "DEVPATH": "DEVPATH",
>           "ID_SERIAL_SHORT": "SERIAL",
>
>   As a result the serial field is empty for virtio devices (noticed first
>   by looking at the UI):
>
>   https://paste.ubuntu.com/p/RzMk7r5ZGH/
>
>           {
>               "firmware_version": null,
>               "name": "vda",
>               "filesystem": null,
>               "id_path": "/dev/vda",
>               "block_size": 2048,
>               "system_id": "xeqrrw",
>   # ...
>               "path": "/dev/disk/by-dname/vda",
>   # ...
>               "serial": "",
>
> --
> You received this bug notification because you are subscribed to MAAS.
> https://bugs.launchpad.net/bugs/1807505
>
> Title:
>   [2.5rc2] serial of a device is not populated for virtio-blk devices
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/maas/+bug/1807505/+subscriptions
>
> Launchpad-Notification-Type: bug
> Launchpad-Bug: product=maas; status=New; importance=Undecided;
> assignee=None;
> Launchpad-Bug-Information-Type: Public
> Launchpad-Bug-Private: no
> Launchpad-Bug-Security-Vulnerability: no
> Launchpad-Bug-Commenters: dmitriis
> Launchpad-Bug-Reporter: Dmitrii Shcherbakov (dmitriis)
> Launchpad-Bug-Modifier: Dmitrii Shcherbakov (dmitriis)
> Launchpad-Message-Rationale: Subscriber (MAAS)
> Launchpad-Message-For: andreserl
>
-- 
Andres Rodriguez (RoAkSoAx)
Ubuntu Server Developer
MSc. Telecom & Networking
Systems Engineer