new file: news/release-0.21.mdwn

[notmuch-wiki] / performance.mdwn

diff --git a/performance.mdwn b/performance.mdwn
index 8515e6a637bb196e6231c9bd115c117dbff1dd9d..a6d7f2e84c465e6b384652c4a2aaa6e2b8655af6 100644 (file)
--- a/performance.mdwn
+++ b/performance.mdwn
@@ -1,7 +1,20 @@
+[[!img notmuch-logo.png alt="Notmuch logo" class="left"]]
 # Optimize notmuch's performance
 
 [[!toc levels=2]]
 
+## Use of ecryptfs slows notmuch down.
+
+I noticed that my `notmuch new` was really slow (several minutes) for
+less then 20 new emails (around 20K in my database).
+
+The performance tests in the notmuch source didn't show any real
+issue, even on a non-encrypted ext4 fs.
+
+After investigation and running different tests, a switch to a
+LUKS-btrfs based filesystem to replace the ext4-ecryptfs resolved the
+issue. It now takes some seconds to index hundreds of messages.
+
 ## Xapian 1.2.x database format: chert vs. flint
 
 Xapian 1.2 (in contrast to 1.0.x) uses a new database format called
@@ -27,7 +40,7 @@ XXX: add examples for different distributions
 Backup your notmuch tags:
 
     $ cd
-    $ notmuch dump notmuch-dump-b4chert
+    $ notmuch dump --output=notmuch-dump-b4chert
 
 Move away your old database:
 
@@ -48,7 +61,7 @@ After the initial import it is definitely not necessary to define
 
 Restore your tags:
 
-    $ notmuch restore notmuch-dump-b4chert
+    $ notmuch restore --input=notmuch-dump-b4chert
 
 Check whether you are on chert now:
 
@@ -80,7 +93,7 @@ This needs xapian 1.2
 Backup your database:
 
     $ cd
-    $ notmuch dump notmuch-dump-b4compact
+    $ notmuch dump --output=notmuch-dump-b4compact
 
 Compact it: