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Add O_DIRECT flag to DD for cache bypass
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Authored by rscheff on May 30 2020, 12:01 PM.
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Details

Summary

FreeBSD DD utility has not had support for the O_DIRECT flag, which
is useful to bypass local caching, e.g. for unconditionally issuing
NFS IO requests during testing.

Test Plan

Mount an NFS export. Perform dd reads twice in a row and validate
that traffic is observed on the network in the 2nd iteration also.

Diff Detail

Lint
Lint Passed
Unit
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Build Status
Buildable 31389
Build 29014: arc lint + arc unit