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In the current docs located at https://docs.mongodb.org/manual/administration/production-notes/#scheduling-for-virtual-devices, we make a blanket assertion that the noop scheduler is recommended in virtualised environments. However, this was derived from the VMWare KB located at: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2011861 which states preconditions that apply to only a minority of use cases.
I would like the docs to replace the recommendation for noop for virtual devices to be replaced with the "cfq" scheduler. The noop scheduler is only recommended when the following conditions are met:
- A replica set topolog or sharded cluster is used
- The VM are located on the same virtual host
- The underlying storage containing the DBpaths is a common blockstore (LUN)
- The hypervisor is VMware based (ESXi etc)
Please note that AWS does not meet these conditions.
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