Check for Linux device name changes
If you're using a Linux storage device driver with several devices, the driver may reassign major and minor numbers from the available range. This can cause your device names to shift after recycling the VM.

When required disks don’t mount, the VM can’t boot properly, and the Azure VM Agent can’t come online.

Use persistent device naming methods
To prevent the issue, use device identifiers that persist across reboots. Instead of relying on dynamic device names like /dev/sdX, use:

• Filesystem labels

• UUIDs

• Derived device paths such as /dev/disk/by-id/ or /dev/disk/by-uuid/

These identifiers remain stable even when the system reassigns device names.

Review Azure guidance on device naming
Azure provides detailed guidance for troubleshooting Linux device name issues to ensure your VM boots consistently.
For more information, see Troubleshoot Linux VM device name changes.