This is an automatic cherry-pick of f93cdd76e016dc0e4deb4d11f67b07f80ac603e1

The original PR was #262 with message:

The buffer holding the message "Starting dockerd with..." is currently too short and the final part, "as storage", will be truncated for certain combinations of settings.

Checklist before requesting a review

• I have performed a self-review of my own code
• I have verified that the code builds perfectly fine on my local system
• I have added tests that prove my fix is effective or that my feature works
• I have commented my code, particularly in hard-to-understand areas
• I have verified that my code follows the style already available in the repository
• I have made corresponding changes to the documentation