Configuring Object Storage as Primary Storage

Nextcloud allows to configure object storages like OpenStack Swift or Amazon Simple Storage Service (S3) or any compatible S3-implementation (e.g. Minio or Ceph Object Gateway) as primary storage replacing the default storage of files.

By default, files are stored in nextcloud/data or another directory configured in the config.php of your Nextcloud instance. This data directory might still be used for compatibility reasons)

Differences from External Storage

When an object store is used as Primary Storage, Nextcloud requires exclusive access over the bucket being used. All metadata (filenames, directory structures, etc) is stored in Nextcloud and not in the object store. The metadata is only stored in the database and the object store only holds the file content by unique identifier.

Performance Implications

Because of this, object stores configured as Primary Storage usually perform better than when using the same object store via the External Storage support application, but the downside is being unable to access the files from outside of Nextcloud. This makes using an object store as Primary Storage distinct from using an object store via External Storage.

Data Backup and Recovery Implications

One impact of using an object store as Primary Storage is that your data backup strategy needs to incorporate this. Your data is longer stored on your Nextcloud server, but your files are also no longer accessible by simply bypassing your Nextcloud server and accessing your object store directly.

Configuration

Primary object stores need to be configured in config.php by specifying the objectstore backend and any backend specific configuration.

Note

Configuring a primary object store on an existing Nextcloud instance will make all existing files on the instance inaccessible.

The configuration has the following structure:

'objectstore' => [
        'class' => 'Object\\Storage\\Backend\\Class',
        'arguments' => [
                ...
        ],
],

OpenStack Swift

The OpenStack Swift backend mounts a container on an OpenStack Object Storage server into the virtual filesystem.

The class to be used is \OC\Files\ObjectStore\Swift

Both openstack v2 and v3 authentication are supported,

V2 Authentication:

'objectstore' => [
        'class' => '\\OC\\Files\\ObjectStore\\Swift',
        'arguments' => [
                'username' => 'username',
                'password' => 'Secr3tPaSSWoRdt7',
                // the container to store the data in
                'bucket' => 'nextcloud',
                'autocreate' => true,
                'region' => 'RegionOne',
                // The Identity / Keystone endpoint
                'url' => 'http://example.com/v2.0',
                // optional on some swift implementations
                'tenantName' => 'username',
                'serviceName' => 'swift',
                // The Interface / url Type, optional
                'urlType' => 'internal'
        ],
],

V3 Authentication:

'objectstore' => [
        'class' => 'OC\\Files\\ObjectStore\\Swift',
        'arguments' => [
                'autocreate' => true,
                'user' => [
                        'name' => 'UserName',
                        'password' => 'Secr3tPaSSWoRdt7',
                        'domain' => [
                                'name' => 'Default',
                        ],
                ],
                'scope' => [
                        'project' => [
                                'name' => 'TenantName',
                                'domain' => [
                                        'name' => 'Default',
                                ],
                        ],
                ],
                'serviceName' => 'swift',
                'region' => 'regionOne',
                'url' => 'http://example.com/v3',
                'bucket' => 'nextcloud',
        ],
],

Simple Storage Service (S3)

The Simple Storage Service (S3) backend mounts a bucket on an Amazon S3 object storage or compatible implementation (e.g. Minio or Ceph Object Gateway) into the virtual filesystem.

The class to be used is \OC\Files\ObjectStore\S3

Amazon-hosted S3:

'objectstore' => [
        'class' => '\\OC\\Files\\ObjectStore\\S3',
        'arguments' => [
                'bucket' => 'my-nextcloud-store',
                'region' => 'us-east-1',
                'key' => 'EJ39ITYZEUH5BGWDRUFY',
                'secret' => 'M5MrXTRjkyMaxXPe2FRXMTfTfbKEnZCu+7uRTVSj',
        ],
],

Non-Amazon hosted S3:

'objectstore' => [
        'class' => '\\OC\\Files\\ObjectStore\\S3',
        'arguments' => [
                'bucket' => 'my-nextcloud-store',
                'hostname' => 's3.example.com',
                'key' => 'EJ39ITYZEUH5BGWDRUFY',
                'secret' => 'M5MrXTRjkyMaxXPe2FRXMTfTfbKEnZCu+7uRTVSj',
                'port' => 8443,
                // required for some non-Amazon S3 implementations
                'use_path_style' => true,
        ],
],

Minimum required parameters are:

bucket [Note: Even if non-Amazon hosted, bucket names must meet AWS S3 naming requirements regardless of what your S3 provider/platform considers acceptable - i.e. no underscores]
key
secret

Note

You will probably need to specify additional parameters beyond these, unless the default values (see below) exactly match your situation. In particular, your region (if Amazon hosted) or hostname (if non-Amazon hosted).

Optional parameters most commonly needing adjustment (and their defaults values if left unconfigured):

region defaults to eu-west-1
storageClass defaults to STANDARD
hostname defaults to s3.REGION.amazonaws.com [Note: If using this parameter (non-Amazon), specify the generic S3 endpoint hostname, not the hostname that contains your bucket name]
use_ssl defaults to true

Optional parameters sometimes needing adjustment:

use_path_style defaults to false
port defaults to 443
sse_c_key has no default

Optional parameters less commonly needing adjustment:

proxy defaults to false
timeout defaults to 15
uploadPartSize defaults to 524288000
putSizeLimit defaults to 104857600
legacy_auth has no default
version defaults to latest
verify_bucket_exists defaults to true [Note: Setting this to false after confirming the bucket has been created may provide a performance benefit, but may not be possible in multibucket scenarios.]

If you are using Amazon S3: the region parameter is required unless you’re happy with the default of eu-west-1. There is no need to override the hostname or port. And storageClass only needs to be modified if you’re using a different configuration at AWS. Lastly, use_path_style is rarely required with Amazon, but some legacy Amazon datacenters may require it.

If you using a non-Amazon hosted S3 store: you will need to set the hostname parameter (and can ignore the region parameter). You may need to use use_path_style if your non-Amazon S3 store does not support requests like https://bucket.hostname.domain/. Setting use_path_style to true configures the S3 client to make requests like https://hostname.domain/bucket instead.

Microsoft Azure Blob Storage

The Azure Blob Storage backend mounts a container on Microsoft’s Azure Blob Storage into the virtual filesystem.

The class to be used is \OC\Files\ObjectStore\Azure

'objectstore' => [
        'class' => '\\OC\\Files\\ObjectStore\\Azure',
        'arguments' => [
                'container' => 'nextcloud',
                'autocreate' => true,
                'account_name' => 'account_name',
                'account_key' => 'xxxxxxxxxx'
        ],
],

Multibucket Object Store

It’s possible to configure Nextcloud to distribute the data over multiple buckets for scalability purposes.

To setup multiple buckets, use 'objectstore_multibucket' storage backend in config.php:

'objectstore_multibucket' => [
        'class' => 'Object\\Storage\\Backend\\Class',
        'arguments' => [
                // optional, defaults to 64
                'num_buckets' => 64,
                // will be postfixed by an integer in the range from 0 to (num_nuckets-1)
                'bucket' => 'nextcloud_',
                ...
        ],
],

Multibucket object store backend maps every user to a range of buckets and saves all files for that user in their corresponding bucket.

Note

While it is possible to change the number of buckets used by an existing Nextcloud instance, the user-to-buckets mapping is only created once, so only newly created users will be mapped to the updated range of buckets.

You can find out more information about upscaling with object storage and Nextcloud in the Nextcloud customer portal.

S3 SSE-C encryption support

Nextcloud supports server side encryption, also known as SSE-C, with compatible S3 bucket provider. The encryption and decryption happens on the S3 bucket side with a key provided by the Nextcloud server.

The key can be specified with the sse_c_key parameter which needs to be provided as a base64 encoded string with a maximum length of 32 bytes. A random key could be generated using the the following command:

openssl rand 32 | base64

The following example shows how to configure the S3 object store with SSE-C encryption support in the objectstore section of the Nextcloud config.php file:

'objectstore' => [
        array (
                'class' => 'OC\\Files\\ObjectStore\\S3',
                'arguments' =>
                array (
                        'bucket' => 'nextcloud',
                        'key' => 'nextcloud',
                        'secret' => 'nextcloud',
                        'hostname' => 's3',
                        'port' => '443',
                        'use_ssl' => true,
                        'use_path_style' => true,
                        'autocreate' => true,
                        'verify_bucket_exists' => true,
                        'sse_c_key' => 'o9d3Q9tHcPMv6TIpH53MSXaUmY91YheZRwuIhwCFRSs=',
                ),
        );
],