Limits
Our buckets use the S3 API, so most S3 tools work with them out of the box. They are not Amazon S3, though. This page explains what works differently, what does not exist yet, and how to work around it.
When a tool asks for a region, enter the location code of your bucket endpoint, for example fra1 for fra1.my-s3.com. Tools that send a fixed region, for example Synology Hyper Backup or Plesk, work too, because our buckets accept the region that a tool sends. Your access key works only for its own bucket and cannot create new buckets. Create additional buckets in the dashboard. Each bucket has a storage size; when it is full, uploads fail until you delete data or increase the size.
Features that do not exist yet
Some S3 features are not available on our buckets yet. A tool that needs them either reports an error or silently skips the setting. The most important gap: versioning and object locking do not exist yet, so an overwrite or a delete is final.
| Feature | Status |
|---|---|
| Object versioning | Not available yet |
| Object Lock (WORM, retention, legal hold) | Not available yet |
Conditional writes (If-None-Match) |
Not available |
| Bucket policies and ACLs | Not available: access is controlled per access key |
| Object and bucket tags | Not available |
| Replication and event notifications | Not available |
| Lifecycle rules | Partly: only expiration and the cleanup of incomplete multipart uploads |
| Signature version 2 | Not available: use signature version 4 |
Tools and setups with known problems
A few tools and setups run into limits of our buckets. Select a tab for the details and the workaround.
The name of an object (its full path in the bucket, for example backups/2026/db.tar) can be at most 510 bytes long.
Tools that encrypt file names make each name much longer than the original. A path that is fine without encryption can then exceed the limit, and the upload of that file fails. rclone with a crypt remote and filename encryption is a common example.
To avoid this, turn off filename encryption and keep only the content encrypted, or keep your folder structure shallow. Backup tools that store their data as chunks with short hash names, for example restic, Kopia or Borg, are not affected.
Web apps that talk to a bucket directly from the browser do not work at the moment. A browser first sends a CORS preflight request, and our endpoint does not answer it with the CORS headers that the browser needs. For the same reason, CORS rules that you set on a bucket have no effect.
Desktop apps, command-line tools and server software are not affected, because they do not send preflight requests.
Very large objects upload more slowly the bigger they get. Upload large files as multipart uploads with parts of at least 10 MiB. Parts that are an exact multiple of 10 MiB work best, because the bucket stores data in blocks of that size.
Most tools (aws-cli, rclone, restic) already use multipart uploads. Check the part or chunk size setting of your tool when uploads of large files stall.