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layout: default
navsection: installguide
title: Configure filesystem storage
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Copyright (C) The Arvados Authors. All rights reserved.

SPDX-License-Identifier: CC-BY-SA-3.0
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Keepstore can store data in local and network-attached POSIX filesystems.

h2. Setting up filesystem mounts

Volumes are configured in the @Volumes@ section of the cluster configuration file.  You may provide multiple volumes for a single keepstore process to manage multiple disks.  Keepstore distributes blocks among volumes in round-robin fashion.

{% include 'assign_volume_uuid' %}

Note that each volume has an AccessViaHosts section indicating that (for example) keep0's /mnt/local-disk directory is volume 0, while keep1's /mnt/local-disk directory is volume 1.

<notextile>
<pre><code>Clusters:
  <span class="userinput">uuid_prefix</span>:
    Volumes:
      <span class="userinput">uuid_prefix</span>-nyw5e-<span class="userinput">000000000000000</span>:
        AccessViaHosts:
          "http://<span class="userinput">keep0.uuid_prefix.example.com</span>:25107": {}
        Driver: Directory
        DriverParameters:
          # The directory that will be used as the backing store.
          Root: /mnt/local-disk

          # When true, read and write operations (for whole 64MiB
          # blocks) on an individual volume will queued and issued
          # serially.  When false, read and write operations will be
          # issued concurrently.
          #
          # May improve throughput if you experience contention when
          # there are multiple requests to the same volume.
          #
          # When using SSDs, RAID, or a shared network filesystem, you
          # probably don't want this.
          Serialize: false

        # How much replication is performed by the underlying
        # filesystem.  (for example, a network filesystem may provide
        # its own replication).  This is used to inform replication
        # decisions at the Keep layer.
        Replication: 1

        # If true, do not accept write or trash operations, only
        # reads.
        ReadOnly: false

        # Storage classes to associate with this volume.  See "Storage
        # classes" in the "Admin" section of doc.arvados.org.
        StorageClasses: null

      <span class="userinput">uuid_prefix</span>-nyw5e-<span class="userinput">000000000000001</span>:
        AccessViaHosts:
          "http://keep1.<span class="userinput">uuid_prefix</span>.example.com:25107": {}
        Driver: Directory
        DriverParameters:
          Root: /mnt/local-disk
</code></pre></notextile>

In the case of a network-attached filesystem, the AccessViaHosts section can have multiple entries. If the filesystem is accessible by all keepstore servers, the AccessViaHosts section can be empty, or omitted entirely.

<notextile>
<pre><code>Clusters:
  <span class="userinput">uuid_prefix</span>:
    Volumes:
      <span class="userinput">uuid_prefix</span>-nyw5e-<span class="userinput">000000000000002</span>:
        AccessViaHosts:
          # This section determines which keepstore servers access the
          # volume. In this example, keep0 has read/write access, and
          # keep1 has read-only access.
          #
          # If the AccessViaHosts section is empty or omitted, all
          # keepstore servers will have read/write access to the
          # volume.
          "http://<span class="userinput">keep0.uuid_prefix.example.com</span>:25107/": {}
          "http://<span class="userinput">keep1.uuid_prefix.example.com</span>:25107/": {ReadOnly: true}
        Driver: Directory
        DriverParameters:
          Root: /mnt/network-attached-filesystem
        Replication: 2
</code></pre></notextile>