Workaround to restore legacy fs mode

[funkypenguin]

This is not so much a bug as a workaround so that others like us can find a solution to restore the "old" fs behaviour..

It's clear that FS / legacy backend is deprecated and not coming back. HOWEVER, it was super-useful in a client's use-case (allowing users to rclone / batch-transfer large files to be consumed by hosted Plex / Jellyfin / Emby apps, which don't necessarily support S3 API). There's really no alternative to Minio in this case.

Note that the docs re pre-existing data indicate that in the case of:

Existing filesystem folders, files, and MinIO backend data

.. then:

MinIO resumes in the legacy filesystem (“Standalone”) mode with no erasure-coding features

So our workaround was simply to create the following format.json in /path-to-existing-data/.minio.sys/:

{"version":"1","format":"fs","id":"avoid-going-into-snsd-mode-legacy-is-fine-with-me","fs":{"version":"2"}}

When Minio starts, it recognizes this as "existing" (above), and happily starts in legacy mode! 👍🏻

Related issues:
#15352
#15455
#14331

[funkypenguin]

@lachesis this may solve the issue you raised in #15455

[harshavardhana]

There is no workaround @funkypenguin if you have an existing setup it continues to work. Fresh setups are not allowed - if you manually wish to create your own format.json you are free to do so.

[naisanzaa]

I wasn't able to find the change log why the filesystem mode was removed. Why was it removed?

[harshavardhana]

I wasn't able to find the change log why the filesystem mode was removed. Why was it removed?

Architecture decision @naisanzaa we are moving on.