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Type:
Improvement
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Resolution: Fixed
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Priority:
Minor - P4
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Affects Version/s: 4.0.3
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Component/s: Upgrade/Downgrade
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Fully Compatible
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v4.0
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Sharding 2018-10-22, Sharding 2018-11-05, Sharding 2018-11-19
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None
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3
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Currently, if a user tries to run a 4.0 mongod binary on data files from FCV 4.2, the following messages appear in the log:
2018-10-04T08:40:21.447-0400 F STORAGE [initandlisten] BadValue: Invalid value for version, found 4.2, expected '4.0' or '3.6'. Contents of featureCompatibilityVersion document in admin.system.version: { _id: "featureCompatibilityVersion", version: "4.2" }. See http://dochub.mongodb.org/core/4.0-feature-compatibility.
2018-10-04T08:40:21.447-0400 F CONTROL [initandlisten] ** IMPORTANT: UPGRADE PROBLEM: Unable to parse the featureCompatibilityVersion document. The data files need to be fully upgraded to version 3.6 before attempting an upgrade to 4.0. If you are upgrading to 4.0, see http://dochub.mongodb.org/core/4.0-upgrade-fcv.