serial console blocked by read only resource lock

[Klaas-]

Hi,
it seems that currently the serial console and the boot diagnostics are not working when a resource is read-only locked.

Boot diagnostics is a read only operation on log data, I am unsure why that is blocked; serial console port is like an ethernet port, it should be working even in locked mode (at least from my point of view, could also be a documentation+better error message fix)

Current error messages in portal:
Boot diagnostics data:
Your virtual machine hasn't written anything to its serial port yet
Serial console:

The serial console connection to the VM encountered an error: 'ERR_BAD_REQUEST'
(409) - Request failed with status code 409

[mbifeld]

Hi @Klaas-, thank you for reporting this issue and creating the related support ticket. This functionality is currently by design as the Serial Console service needs to write a connection string to the boot diagnostics storage account to set up the connection.

Later this year (ETA November), we are planning to migrate Serial Console off the dependency on boot diagnostics storage accounts. So it will work with the lock in place on the storage account (or even no boot diagnostics storage account at all). I'll work on updating the documentation in the meantime.

Note that the November change will just affect Serial Console, not serial logs.

[Klaas-]

Any updates @mbifeld ? :)

[mbifeld]

Hi @Klaas-, my apologies for not providing an update here. The migration to remove Serial Console's dependency on boot diagnostics storage accounts was delayed to Q2 of CY 2026 (targeting April). A general notice in the docs is added here.