X-Git-Url: https://git.cworth.org/git?p=notmuch-wiki;a=blobdiff_plain;f=performance.mdwn;h=14f96a01363c643671f4062bb8cfaf45e7a209ff;hp=e686cabd1a55fe6b3cdd451b8001ee73e831f320;hb=f74f269a84d927c226418ff74d25daa779b5b854;hpb=00e5d4b6f8f9357e1d0da2c5eb7b4b9ec043ec3b

diff --git a/performance.mdwn b/performance.mdwn
index e686cab..14f96a0 100644
--- a/performance.mdwn
+++ b/performance.mdwn
@@ -1,69 +1,76 @@
+[[!img notmuch-logo.png alt="Notmuch logo" class="left"]]
 # Optimize notmuch's performance
 
-## Xapian 1.2.x database format: chert vs. flint
+[[!toc levels=2]]
 
-Xapian 1.2 (in contrast to 1.0.x) uses a new database format called
-`chert` which is a lot faster than the old format `flint`.
+## Use of ecryptfs slows notmuch down.
 
-Check whether you are on chert or flint:
+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 database format: chert vs. flint vs. glass
+
+Depending on the Xapian version that was used during the initial notmuch
+database creation, you might use another database format than the most recent
+one, which is often faster.
+
+Check whether you are on chert, flint or glass:
 
     $ ls $(notmuch config get database.path)/.notmuch/xapian/iam*
-    iamchert
+    iamglass
 
-If it does not say `iamchert`, but `iamflint`, than you should migrate
-(read on).
+If it does not say `iamglass`, but `iamchert` or `iamflint`, than you should
+migrate (read on).
 
-There might be a file named `flintlock`, it is no indicator for your
-database format, but also used in case of `chert`.
+There might be a file named `flintlock`, it is no indicator for your database
+format, but also used in case of `chert`.
 
-### Migrate from flint to chert
+### Migrate from an older format to the most recent one (glass)
 
-1. make sure you are using xapian 1.2.x (depends on your distribution)
+Make sure you are using xapian 1.4.x (depends on your distribution)
 
-XXX: add examples
+XXX: add examples for different distributions
 
-2. Backup your notmuch tags:
+Backup your notmuch tags:
 
     $ cd
-    $ notmuch dump notmuch-dump-b4chert
+    $ notmuch dump --output=notmuch-dump-oldformat
 
-3. Move away your old database:
+Move away your old database:
 
-    $ mv $(notmuch config get database.path)/.notmuch/ notmuch-db-b4chert
+    $ mv $(notmuch config get database.path)/.notmuch/ notmuch-db.bak
 
-4. Find and import your messages, a new and fresh database will be
+Find and import your messages, a new and fresh database will be
 created:
 
-    $ XAPIAN_PREFER_CHERT=1 notmuch new
+    $ notmuch new
 
-I did not need the `XAPIAN_PREFER_CHERT`, but am not sure whether
-there are situations making it necessary (certain compile-time options
-to xapian?). This note is just here to be extended or removed by
-somebody more knowledgeable.
+Restore your tags:
 
-After the initial import it is definitely not necessary to define
-`XAPIAN_PREFER_CHERT` for subsequent calls of `notmuch new`.
+    $ notmuch restore --input=notmuch-dump-oldformat
 
-5. Restore your tags:
-
-    $ notmuch restore notmuch-dump-b4chert
-
-6. Check whether you are on chert now:
+Check whether you are on glass now:
 
     $ ls $(notmuch config get database.path)/.notmuch/xapian/iam*
-    iamchert
+    iamglass
 
-  If it says `iamflint`, most likely you are still using xapian 1.0.x.
+  If it says `iamflint` or `iamchert`, most likely you are still using an old
+  xapian version.
 
-7. Clean-up
+Clean-up: if you are sure everything is fine, you can delete the old
+things. The dump of your tags you might want to keep anyway as a
+backup - on the other hand you should have some mechanism in place to
+make regular backups of your notmuch database:
 
-If you are sure everything is fine, you can delete the old things. The
-dump of your tags you might want to keep anyway as a backup - on the
-other hand you should have some mechanism in place to make regular
-backups of your notmuch database:
-
-    $ rm notmuch-dump-b4chert
-    $ rm -R notmuch-db-b4chert
+    $ rm notmuch-dump-oldformat
+    $ rm -R notmuch-db.bak
 
 ### Compact your database
 
@@ -80,7 +87,7 @@ This needs xapian 1.2
 Backup your database:
 
     $ cd
-    $ notmuch dump notmuch-dump-b4compact
+    $ notmuch dump --output=notmuch-dump-b4compact
 
 Compact it:
 
@@ -95,9 +102,8 @@ Remove old and renamed compacted, if compacting went well:
 
 ### More information about this in the email archives:
 
-* [Carl Worth](http://notmuchmail.org/pipermail/notmuch/2010/001105.html)
-
-* [Sebastian Spaeth](http://notmuchmail.org/pipermail/notmuch/2011/004048.html)
+* [Carl Worth](https://notmuchmail.org/pipermail/notmuch/2010/001105.html)
 
-* [Pieter Praet](http://notmuchmail.org/pipermail/notmuch/2011/004175.html)
+* [Sebastian Spaeth](https://notmuchmail.org/pipermail/notmuch/2011/004048.html)
 
+* [Pieter Praet](https://notmuchmail.org/pipermail/notmuch/2011/004175.html)