I would closely monitor what really happens. big files uploaded in parts multiple “chunks” are temporarily stored as .part and later combined into a full file at the end.. many things could go wrong, chunks could be to large, downloading chunks to combine them could fail, temp storage could exhaust etc..
this references could help troubleshooting:
- Uploading big files > 512MB — Nextcloud latest Administration Manual latest documentation
- 404 error on MOVE-Request when assembling chunked upload
- Use MultipartUpload for uploading chunks to s3 by juliusknorr · Pull Request #27034 · nextcloud/server · GitHub
- https://github.com/nextcloud/server/issues/39088
- S3 random storage problem on large files
- Configuring Object Storage as Primary Storage — Nextcloud latest Administration Manual latest documentation
- Chunked file upload — Nextcloud latest Developer Manual latest documentation
there are also config settings which might help (see config.sample.php for details):
/**
* Store part files created during upload in the same storage as the upload
* target. Setting this to false stores part files in the root of the user's
* folder, which may be necessary for external storage with limited rename
* capabilities.
*
* Defaults to ``true``
*/
'part_file_in_storage' => true,
/**
* Allow storage systems that do not support modifying existing files to overcome
* this limitation by removing files before overwriting.
*
* Defaults to ``false``
*/
'localstorage.unlink_on_truncate' => false,