e9857d616d
This patch is part of the docs migration for Cinder. It is more or less a drag and drop of the docs from openstack-manuals admin-guide directory. I needed to change some syntax to work with Cinder's more stringent doc build. Note that the purpose of this patch is just to get the documentation back to an accessible location. Later patches will clean up the organization and content. Change-Id: Ib3f9255e0f9f2ff42a0ee4126607ff319a3d901e
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1.7 KiB
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47 lines
1.7 KiB
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.. _ratelimit_volume_copy_bandwidth:
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================================
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Rate-limit volume copy bandwidth
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================================
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When you create a new volume from an image or an existing volume, or
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when you upload a volume image to the Image service, large data copy
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may stress disk and network bandwidth. To mitigate slow down of data
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access from the instances, OpenStack Block Storage supports rate-limiting
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of volume data copy bandwidth.
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Configure volume copy bandwidth limit
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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To configure the volume copy bandwidth limit, set the
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``volume_copy_bps_limit`` option in the configuration groups for each
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back end in the ``cinder.conf`` file. This option takes the integer of
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maximum bandwidth allowed for volume data copy in byte per second. If
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this option is set to ``0``, the rate-limit is disabled.
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While multiple volume data copy operations are running in the same back
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end, the specified bandwidth is divided to each copy.
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Example ``cinder.conf`` configuration file to limit volume copy bandwidth
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of ``lvmdriver-1`` up to 100 MiB/s:
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.. code-block:: ini
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[lvmdriver-1]
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volume_group=cinder-volumes-1
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volume_driver=cinder.volume.drivers.lvm.LVMVolumeDriver
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volume_backend_name=LVM
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volume_copy_bps_limit=104857600
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.. note::
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This feature requires libcgroup to set up blkio cgroup for disk I/O
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bandwidth limit. The libcgroup is provided by the cgroup-bin package
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in Debian and Ubuntu, or by the libcgroup-tools package in Fedora,
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Red Hat Enterprise Linux, CentOS, openSUSE, and SUSE Linux Enterprise.
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.. note::
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Some back ends which use remote file systems such as NFS are not
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supported by this feature.
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