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navsection: installguide
title: 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.

Note that each volume has a UUID, like "zzzzz-nyw5e-0123456789abcde". You can assign these manually, but once assigned they should not be changed.

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://keep0.zzzzz.example.com: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.zzzzz.example.com:25107/": {}
        Driver: Directory
        DriverParameters:
          Root: /mnt/local-disk
</code></pre></notextile>

In the case of a network-attached filesystem accessible by all keepstore servers, the AccessViaHosts section is omitted.

<notextile>
<pre><code>Clusters:
  <span class="userinput">uuid_prefix</span>:
    Volumes:
      # This volume is used by all keepstore servers.
      <span class="userinput">uuid_prefix</span>-nyw5e-<span class="userinput">000000000000002</span>:
        Driver: Directory
        DriverParameters:
          Root: /mnt/network-attached-filesystem
        Replication: 2
</code></pre></notextile>