From: Matthew Sakai Date: Thu, 7 Mar 2024 21:02:35 +0000 (-0500) Subject: dm vdo: document minimum metadata size requirements X-Git-Tag: v6.9-rc1~148^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cb824724dccb3195d22cad96e7b65fe13621d0a6;p=thirdparty%2Fkernel%2Flinux.git dm vdo: document minimum metadata size requirements Signed-off-by: Matthew Sakai Signed-off-by: Mike Snitzer --- diff --git a/Documentation/admin-guide/device-mapper/vdo.rst b/Documentation/admin-guide/device-mapper/vdo.rst index a3572582ead8f..7e1ecafdf91e3 100644 --- a/Documentation/admin-guide/device-mapper/vdo.rst +++ b/Documentation/admin-guide/device-mapper/vdo.rst @@ -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 ================