d987062d15
This patch reverts the removal of the collection of volume stats
from the vCenter. Of course there is a performance hit when
collecting volume stats against a backend as compared to doing
nothing. The problem with not having any stats collection is that
the scheduler can't schedule properly against this driver, especially
when there are multiple of them deployed and heterogeniously against
other backends. This revert fixes existing deployments against
this backend.
This patch includes a new vmware driver config optiont that allows one
to enable the stats collection, so that a deployment with this driver
can actually work with the scheduler. When a driver doesn't report
any statistics, the scheduler has no way to determine the capacity
utilization of the driver and will always assume it can take a
provisioning request. This is especially problematic in a
heterogeniously deployed environment, where other drivers do report
valid stats.
This reverts commit f3ee3dbf4e.
Change-Id: Ifdd9b89e00de692a7a9e121ed421b921aa8bfc70
Closes-Bug: 1859864
24 lines
1.3 KiB
YAML
24 lines
1.3 KiB
YAML
---
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upgrade:
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VMware vmdk driver: The vmware vmdk driver had its get_volume_stats
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removed in a previous release due to a potential performance hit of 20%
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at a high load. The problem with reporting ``unknown`` back to the
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scheduler, is that it effectively removes cinder's ability to properly
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schedule based on capacity utilization. When this driver is enabled in a
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heterogenous environment without properly reporting utilization
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statistics, the scheduler's capacity filter will always allow this driver
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to service a provisioning request. Without reporting the backend stats,
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the capacity filter also can't determine the reserved_percentage as well
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as the max_over_subscription_ratio. To enable the collection of stats
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set ``vmware_enable_volume_stats`` to True in the driver section of
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cinder.conf. The default setting is False. Keep in mind that there may
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be a degradation in performance on the vcenter when enabling this setting.
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fixes:
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VMware vmdk driver: The collection of volume stats, which had been
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disabled, may now be turned on by using the ``vmware_enable_volume_stats``
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configuration option. The default for this option is False (no
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stats collection). Be aware that enabling volume stats may cause
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performance issues under high load.
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