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
1.7 KiB
Rate-limit volume copy bandwidth
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.
Configure volume copy bandwidth limit
To configure the volume copy bandwidth limit, set the
volume_copy_bps_limit option in the configuration groups
for each back end in the cinder.conf file. This option
takes the integer of maximum bandwidth allowed for volume data copy in
byte per second. If this option is set to 0, the rate-limit
is disabled.
While multiple volume data copy operations are running in the same back end, the specified bandwidth is divided to each copy.
Example cinder.conf configuration file to limit volume
copy bandwidth of lvmdriver-1 up to 100 MiB/s:
[lvmdriver-1]
volume_group=cinder-volumes-1
volume_driver=cinder.volume.drivers.lvm.LVMVolumeDriver
volume_backend_name=LVM
volume_copy_bps_limit=104857600Note
This feature requires libcgroup to set up blkio cgroup for disk I/O bandwidth limit. The libcgroup is provided by the cgroup-bin package in Debian and Ubuntu, or by the libcgroup-tools package in Fedora, Red Hat Enterprise Linux, CentOS, openSUSE, and SUSE Linux Enterprise.
Note
Some back ends which use remote file systems such as NFS are not supported by this feature.