Added a section about kernel tuning.

diff --git a/INSTALL b/INSTALL
index c48db87e4b785d00e303aa11885b9b57a7690334..e4cdd89bf78c8b5181ab4098246f30c4ed33df41 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -88,3 +88,15 @@ adduser www-data ais
 change apache umask in /etc/apache2/envvars from 022 to 002 so that new folders are group writables. If there is no such line, just add "umask 002" at the end of the file.
 
 a2enmod ssl headers rewrite
+
+= Kernel tuning
+===============
+
+I suggest you add these lines to your /etc/sysctl.conf file:
+
+# for postgres: a process may use up to 768MB of RAM
+kernel.shmmax=805306368
+# Udp recv queue max size. Note this is not the max size a default socket will
+get. 256*1024-1 => doubled by kernel = 512KB
+net.core.rmem_max=262143
+