6.0

4 Click OK.
Set Storage DRS Runtime Rules
Set Storage DRS triggers and configure advanced options for the datastore cluster.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 (Optional) Select or deselect the Enable I/O metric for SDRS recommendations check box to enable or
disable I/O metric inclusion.
When you disable this option, vCenter Server does not consider I/O metrics when making Storage DRS
recommendations. When you disable this option, you disable the following elements of Storage DRS:
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I/O load balancing among datastores within a datastore cluster.
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Initial placement for virtual disks based on I/O workload. Initial placement is based on space only.
2 (Optional) Set Storage DRS thresholds.
You set the aggressiveness level of Storage DRS by specifying thresholds for used space and I/O
latency.
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Use the Utilized Space slider to indicate the maximum percentage of consumed space allowed
before Storage DRS is triggered. Storage DRS makes recommendations and performs migrations
when space use on the datastores is higher than the threshold.
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Use the I/O Latency slider to indicate the maximum I/O latency allowed before Storage DRS is
triggered. Storage DRS makes recommendations and performs migrations when latency is higher
than the threshold.
NOTE The Storage DRS I/O Latency threshold for the datastore cluster should be lower than or
equal to the Storage I/O Control congestion threshold.
3 (Optional) Configure advanced options.
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No recommendations until utilization difference between source and destination is: Use the slider
to specify the space utilization difference threshold. Utilization is usage * 100/capacity.
This threshold ensures that there is some minimum difference between the space utilization of the
source and the destination. For example, if the space used on datastore A is 82% and datastore B is
79%, the difference is 3. If the threshold is 5, Storage DRS will not make migration
recommendations from datastore A to datastore B.
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Evaluate I/O load every: Specify how often Storage DRS should assess space and I/O load
balancing.
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I/O imbalance threshold: Use the slider to indicate the aggressiveness of I/O load balancing.
Lowering this value makes I/O load balancing less aggressive. Storage DRS computes an I/O
fairness metric between 0 and 1, which 1 being the fairest distribution. I/O load balancing runs only
if the computed metric is less than 1 - (I/O imbalance threshold / 100).
4 Click Next.
vSphere Administration with the vSphere Client
370 VMware, Inc.