3175ebd7b6
Rate-limit of volume copy bandwidth per each Cinder backend is implemented in Kilo. This patch adds documentation for it. Change-Id: I6b887cf67b6fd0abf0cacf99c30fbe6c45a5dad6
48 lines
2.3 KiB
XML
48 lines
2.3 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<section xmlns="http://docbook.org/ns/docbook"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude"
|
|
xmlns:xlink="http://www.w3.org/1999/xlink"
|
|
version="5.0"
|
|
xml:id="ratelimit-volume-copy-bandwidth">
|
|
<title>Rate-limit volume copy bandwidth</title>
|
|
<para>When you create a new volume from an image or an existing
|
|
volume, or when you upload a volume image to the Image Service,
|
|
large data copy may stress disk and network bandwidth.
|
|
To mitigate slow down of data access from the instances,
|
|
OpenStack Block Storage supports rate-limiting of volume data
|
|
copy bandwidth.</para>
|
|
<simplesect>
|
|
<title>Configure volume copy bandwidth limit</title>
|
|
<para>To configure the volume copy bandwidth limit, set the
|
|
<option>volume_copy_bps_limit</option> option in the
|
|
configuration groups for each back end in the
|
|
<filename>cinder.conf</filename> file. This option takes
|
|
the integer of maximum bandwidth allowed for volume data
|
|
copy in byte per second. If this option is set to
|
|
<literal>0</literal>, the rate-limit is disabled.</para>
|
|
<para>While multiple volume data copy operations are running
|
|
in the same back end, the specified bandwidth is divided to
|
|
each copy.</para>
|
|
<para>Example <filename>cinder.conf</filename> configuration file
|
|
to limit volume copy bandwidth of <literal>lvmdriver-1</literal>
|
|
up to 100 MiB/s:</para>
|
|
<programlisting language="ini">[lvmdriver-1]
|
|
volume_group=cinder-volumes-1
|
|
volume_driver=cinder.volume.drivers.lvm.LVMISCSIDriver
|
|
volume_backend_name=LVM_iSCSI
|
|
volume_copy_bps_limit=104857600</programlisting>
|
|
<note>
|
|
<para>This feature requires libcgroup to set up blkio cgroup
|
|
for disk I/O bandwidth limit. The libcgroup is provided
|
|
by the <package>cgroup-bin</package> package in Debian
|
|
and Ubuntu, or by the <package>libcgroup-tools</package>
|
|
package in Fedora, Red Hat Enterprise Linux, CentOS, openSUSE, and
|
|
SUSE Linux Enterprise.</para>
|
|
</note>
|
|
<note>
|
|
<para>Some back ends which use remote file systems such as NFS
|
|
are not supported by this feature.</para>
|
|
</note>
|
|
</simplesect>
|
|
</section>
|