Ubuntu on Azure - flood of sr0 errors in syslog even on new deployments

I am experiencing issues with installation of an Ubuntu server (22.04 LTS) on Azure using the standard portal options (either create VM and select Ubuntu or direct create Ubuntu server).Can anyone explain how to solve this?

Just selecting the standard options will give some errors in the syslog.

Apr 16 07:10:19 xx01 kernel: [    1.208209] sr 1:0:0:2: [sr0] scsi-1 driveApr 16 07:10:19 xx01 kernel: [    1.255246] sr 1:0:0:2: Attached scsi CD-ROM sr0Apr 16 07:10:19 xx01 kernel: [   10.245301] sr 1:0:0:2: [sr0] tag#34 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0sApr 16 07:10:19 xx01 kernel: [   10.245304] sr 1:0:0:2: [sr0] tag#34 Sense Key : Not Ready [current] Apr 16 07:10:19 xx01 kernel: [   10.245307] sr 1:0:0:2: [sr0] tag#34 Add. Sense: Medium not present - tray openApr 16 07:10:19 xx01 kernel: [   10.245309] sr 1:0:0:2: [sr0] tag#34 CDB: Read(10) 28 00 00 00 00 02 00 00 02 00Apr 16 07:10:19 xx01 kernel: [   10.245311] I/O error, dev sr0, sector 8 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2Apr 16 07:10:19 xx01 kernel: [   10.249793] sr 1:0:0:2: [sr0] tag#98 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0sApr 16 07:10:19 xx01 kernel: [   10.249795] sr 1:0:0:2: [sr0] tag#98 Sense Key : Not Ready [current] Apr 16 07:10:19 nb01 kernel: [   10.249798] sr 1:0:0:2: [sr0] tag#98 Add. Sense: Medium not present - tray openApr 16 07:10:19 nb01 kernel: [   10.249800] sr 1:0:0:2: [sr0] tag#98 CDB: Read(10) 28 00 00 00 00 02 00 00 02 00Apr 16 07:10:19 nb01 kernel: [   10.249801] I/O error, dev sr0, sector 8 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2Apr 16 07:10:19 nb01 kernel: [   10.252488] Buffer I/O error on dev sr0, logical block 1, async page readApr 16 07:10:19 nb01 systemd-udevd[183]: sr0: Process '/usr/bin/unshare -m /usr/bin/snap auto-import --mount=/dev/sr0' failed with exit code 1.Apr 16 07:10:28 nb01 cloud-init[1627]: Cloud-init v. 23.4.4-0ubuntu0~22.04.1 finished at Tue, 16 Apr 2024 07:10:28 +0000. Datasource DataSourceAzure [seed=/dev/sr0].  Up 24.75 seconds

After reboot (nothing else done) the syslog is flooded (thousands) with:

Apr 16 07:12:28 xx01 kernel: [   10.961581] sr 0:0:0:2: [sr0] tag#184 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961585] sr 0:0:0:2: [sr0] tag#185 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961587] sr 0:0:0:2: [sr0] tag#186 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961590] sr 0:0:0:2: [sr0] tag#187 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961592] sr 0:0:0:2: [sr0] tag#188 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961594] sr 0:0:0:2: [sr0] tag#189 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961596] sr 0:0:0:2: [sr0] tag#190 unaligned transferApr 16 07:12:28 xx01 kernel: [   10.961599] sr 0:0:0:2: [sr0] tag#191 unaligned transfer

It looks like an issue with the cloudinit cdrom. I tried to disable cloudinit deployment through chaniging /etc/waagent.conf and setting cloudinit deployment to no, then commenting out the mount option for cloudinit in /etc/fstab

The /etc/fstab persisted through boot as did the change in /etc/waagent.conf, but still the same sr0 unaligned transfer errors.

lsblk shows:

NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTSloop0     7:0    0 63.9M  1 loop /snap/core20/2182loop1     7:1    0   87M  1 loop /snap/lxd/27948loop2     7:2    0 39.1M  1 loop /snap/snapd/21184sda       8:0    0   30G  0 disk ├─sda1    8:1    0 29.9G  0 part /├─sda14   8:14   0    4M  0 part └─sda15   8:15   0  106M  0 part /boot/efisdb       8:16   0    8G  0 disk └─sdb1    8:17   0    8G  0 part sr0      11:0    1 1024M  0 rom  

All deployments on west-europe azure region.