As Exoscale’s Simple Object Storage (or SOS) is S3 compatible, all tools using the S3 API can be used with SOS. Mountpoint is an open source S3 client by AWS that you can use to access the objects in your bucket like files on a filesystem. The ideal use case is for read-heavy applications that require large amounts of data (e.g. data lakes, machine learning training data, ETL).


Install the current version of AWS Mountpoint for your environment. AWS offers precompiled binaries for different platforms here


Create an Exoscale IAM api-key / secret with permissions to access your SOS bucket. Save it in your home directory in .aws/credentials under a profile. For example exomount:

aws_access_key_id = EXO1234567890
aws_secret_access_key = <your api-secret here>


Create a directory where you want to mount the bucket:

$ mkdir mnt

Mount the bucket with the endpoint of the zone where the bucket was created (for a complete list of SOS endpoints look here). In this example the bucket mybucket was created in our Zurich zone ch-dk-2:

$ mount-s3  --profile exomount --endpoint-url  mybucket mnt

Now you can copy files to the mounted bucket:

$ cp backup.tgz mnt

and list them:

$ ls -l mnt
total 1
-rw-r--r-- 1 exouser exouser 524288 Jul 7 11:23 backup.tgz

Read the contents:

$ md5sum mnt/backup.tgz
45e4be3ff8d14c966c61cca131f8b8e1 mnt/backup.tgz

If you try to delete the file you get an error:

$ rm mnt/backup.tgz
rm: cannot remove 'mnt/backup.tgz': Operation not permitted

By default, Mountpoint does not allow to delete files on a mounted bucket. If you want to do this you must add the option --allow-delete when mounting the bucket.

If you no longer need the mounted bucket you can unmount it:

$ umount mnt


SOS is an object store, and although Mountpoint helps bridge the gap by presenting SOS objects as files, it doesn’t create a POSIX-compliant filesystem. This means some filesystem operations might not behave as expected.

For example, it’s not possible to modify existing files (only overwrite) or rename directories and it does not support symbolic links or file locking. More details can be found in the Mountpoint documentation here.

AWS Mountpoint in combination with SOS does not support server-side encryption (SSE).