Commit 8a96e60d authored by Bernardo Dal Seno's avatar Bernardo Dal Seno

Reuse current spindles in design for partitioned

Renaming the current parameters dealing with spindles is nice, as their
meaning would be clearer, but that would mean changing a lot of code,
change external interfaces, and renaming internal variables for little
benefit. Also, instance policies would end up containing two related
parameters, one used when exclusive_storage is enabled, and the other when
disabled. Reusing the existing parameters by changing slightly their
semantics makes more sense.
Signed-off-by: default avatarBernardo Dal Seno <bdalseno@google.com>
Reviewed-by: default avatarGuido Trotter <ultrotter@google.com>
parent f583e7ad
......@@ -86,12 +86,22 @@ accounted separately in allocation and balancing.
There is already a concept of spindles in Ganeti. It's not related to
any actual spindle or volume count, but it's used in ``spindle_use`` to
measure the pressure of an instance on the storage system and in
``spindle_ratio`` to balance the I/O load on the nodes. These two
parameters will be renamed to ``storage_io_use`` and
``storage_io_ratio`` to reflect better their meaning. When
``exclusive_storage`` is enabled, such parameters are ignored, as
balancing the use of storage I/O is already addressed by the exclusive
assignment of PVs.
``spindle_ratio`` to balance the I/O load on the nodes. When
``exclusive_storage`` is enabled, these parameters as currently defined
won't make any sense, so their meaning will be changed in this way:
- ``spindle_use`` refers to the resource, hence to the actual spindles
(PVs in LVM), used by an instance. The values specified in the instance
policy specifications are compared to the run-time numbers of spindle
used by an instance. The ``spindle_use`` back-end parameter will be
ignored.
- ``spindle_ratio`` in instance policies and ``spindle_count`` in node
parameters are ignored, as the exclusive assignment of PVs already
implies a value of 1.0 for the first, and the second is replaced by
the actual number of spindles.
When ``exclusive_storage`` is disabled, the existing spindle parameters
behave as before.
Dedicated CPUs
--------------
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment