dm vdo: document minimum metadata size requirements

Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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Matthew Sakai 2024-03-07 16:02:35 -05:00 committed by Mike Snitzer
parent 2a7f925bc2
commit cb824724dc
1 changed files with 11 additions and 0 deletions

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@ -34,6 +34,17 @@ The repo also contains additional userspace tools which can be used to
inspect a vdo target's on-disk metadata. Fortunately, these tools are
rarely needed except by dm-vdo developers.
Metadata requirements
=====================
Each vdo volume reserves 3GB of space for metadata, or more depending on
its configuration. It is helpful to check that the space saved by
deduplication and compression is not cancelled out by the metadata
requirements. An estimation of the space saved for a specific dataset can
be computed with the vdo estimator tool, which is available at:
https://github.com/dm-vdo/vdoestimator/
Target interface
================