From f8687564d064ad513972835a7c386f482b56a715 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Mon, 31 Aug 2020 04:33:37 +0000 Subject: [PATCH] doc: expand on indexBatchSize regarding fragmentation And change the documentation reference in -tuning to point to the -index manpage while we're at it. --- Documentation/public-inbox-index.pod | 5 +++-- Documentation/public-inbox-tuning.pod | 6 ++++-- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/Documentation/public-inbox-index.pod b/Documentation/public-inbox-index.pod index 207b2ed8..936516f8 100644 --- a/Documentation/public-inbox-index.pod +++ b/Documentation/public-inbox-index.pod @@ -129,8 +129,9 @@ below. When using rotational storage but abundant RAM, using a large value (e.g. C<500m>) with C<--sequential-shard> can -significantly speed up the initial index and full C<--reindex> -invocations (but not incremental updates). +significantly speed up and reduce fragmentation during the +initial index and full C<--reindex> invocations (but not +incremental updates). Available in public-inbox 1.6.0 (PENDING). diff --git a/Documentation/public-inbox-tuning.pod b/Documentation/public-inbox-tuning.pod index b4e7698b..f5a25676 100644 --- a/Documentation/public-inbox-tuning.pod +++ b/Documentation/public-inbox-tuning.pod @@ -74,7 +74,7 @@ sharding imposes a performance penalty for read-only queries. Users with large amounts of RAM are advised to set a large value for C as documented in -L. +L. C users on Linux 4.0+ are advised to try the C<--perf-same_cpu_crypt> C<--perf-submit_from_crypt_cpus> @@ -95,7 +95,9 @@ Disabling copy-on-write also disables checksumming, thus C Fortunately, these SQLite and Xapian indices are designed to recoverable from git if missing. -Disabling CoW does not prevent all fragmentation. +Disabling CoW does not prevent all fragmentation. Large values +of C also limit fragmentation during +the initial index. Avoid snapshotting subvolumes containing Xapian and/or SQLite indices. Snapshots use CoW despite our efforts to disable it, resulting -- 2.44.0