diff --git a/doc/admin-guide-cloud/source/compute-flavors.rst b/doc/admin-guide-cloud/source/compute-flavors.rst index 490d792c02..297c58f0f5 100644 --- a/doc/admin-guide-cloud/source/compute-flavors.rst +++ b/doc/admin-guide-cloud/source/compute-flavors.rst @@ -163,6 +163,40 @@ Memory limits $ nova flavor-key m1.medium set quota:memory_shares_level=custom $ nova flavor-key m1.medium set quota:memory_shares_share=15 +Disk I/O limits + For VMware, you can configure the resource limits for disk + with control parameters. + + Use these optional parameters to limit the disk utilization, + guarantee disk allocation, and to specify shares + used in case of resource contention. This allows the VMWare + driver to enable disk allocations for the running instance. + + - ``disk_io_limit``: Specifies the upper limit for disk + utilization in I/O per second. The utilization of a + virtual machine will not exceed this limit, even + if there are available resources. The default value + is -1 which indicates unlimited usage. + + - ``disk_io_reservation``: Specifies the guaranteed minimum disk + allocation in terms of IOPS. + + - ``disk_io_shares_level``: Specifies the allocation + level. This can be ``custom``, ``high``, ``normal`` or ``low``. + If you choose custom, set the number of shares + using ``disk_io_shares_share``. + + - ``disk_io_shares_share``: Specifies the number of shares + allocated in the event that ``custom`` is used. + When there is resource contention, this value is used + to determine the resource allocation. + + The example below sets the ``disk_io_reservation`` to 2000 IOPS. + + .. code:: console + + $ nova flavor-key m1.medium set quota:disk_io_reservation=2000 + Disk tuning Using disk I/O quotas, you can set maximum disk write to 10 MB per second for a VM user. For example: