One last question… You used the flag “dsync” that means that no caching is involved in the process and that write operations are performed directly on the media. What does the mender client require this ?
Caching is involved but only 1-4 MB is cached at a time.
It used to rely completely on the cache. but this caused problems in some environments. More information about it here [MEN-2285] - Mender and CFEngine (by Northern.tech) Jira