File Locking and (S3) Object Storage or NFS (v3/v4)

[solracsf]

The object storage service’s API should gracefully handle the situation if >1 PHP workers attempt to write to the same file simultaneously. If locking is handled by both Nextcloud (at the application level) and by the storage backend (API level), a conflicting situation can occur where files cannot be updated or deleted due to file locks.

Similar behaviour applies for NFS and file locking.

Shouldn't the Administration > Overview warning and the check be disabled if the primary storage is S3? In other words, shouldn't we recommend to disable filelocking if using S3 or NFS as the storage backend?

[SimplyCorbett]

Haven't run into this situation but I use ceph.

Deleting files can take a long time but nextcloud will continue to gradually delete them even after closing the page until they are gone.

So I believe even if you run into a file lock issue on the S3 backend nextcloud will still eventually delete them.

As far as editing goes that's a possible issue. I'll have to check into it later today or tomorrow since I don't use nextcloud to edit files.

[sebastiansterk]

If the warning will stay, then the file locking must be improved. currently you will face issues when using s3 as primary storage with enabled file locking on nextcloud side.

[SimplyCorbett]

If the warning will stay, then the file locking must be improved. currently you will face issues when using s3 as primary storage with enabled file locking on nextcloud side.

How do you intend to improve nextclouds file locking? Both S3 and NFS have their own built in file locking.

[sebastiansterk]

If the warning will stay, then the file locking must be improved. currently you will face issues when using s3 as primary storage with enabled file locking on nextcloud side.

How do you intend to improve nextclouds file locking? Both S3 and NFS have their own built in file locking.

This is why the warning should be disabled if the primary storage is s3 ;)

[solracsf]

See also #288 (comment)

[skjnldsv]

shouldn't we recommend to disable filelocking if using S3 or NFS as the storage backend?

No
The file locking also applies to local files. There might be changes that does not go through the S3 storage.