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+====== Linux OS Tuning/Optimizations ======
+===== High i/o wait tuning for File Servers  =====
+Under “Server”→“General” tab, change “Priority” configuration to “-19”. Process priority can be set from -19 to 20, -19 is the highest, 20 is the lowest.
+===== Change to 'deadline' I/O scheduler =====
+  * From command line (change the device 'sda' to appropriate device):
+  echo “deadline” > /sys/block/sda/queue/scheduler
+  * kernel parameter, change /boot/grub/menu.lst, add kernel parameter
+  elevator=deadline
+===== Change VM parameters =====
+There are two variables which control the behaviour of VM flushing and allocation and affect network and disk performance
+  * vm.dirty_background_ratio
+  * vm.dirty_ratio
+To set these values from command line
+  echo 20 > /proc/sys/vm/dirty_background_ratio
+  echo 60 > /proc/sys/vm/dirty_ratio
+to make it permanent, edit /etc/sysctl.conf:
+  vm.dirty_background_ratio = 20
+  vm.dirty_ratio = 60
+===== Increase readahead =====
+To get current readahead value:
+  $ blockdev --getra /dev/sda
+To increase it to a higher value like 16K:
+  $ blockdev --setra 16384 /dev/sda
+===== Disable updating access time stamp for file system =====
+Edit /etc/fstab, remove "atime" attribute if there is, add "noatime" attribute. The noatime change can significantly improve your server's file i/o performance.
+<code>
+#sample /etc/fstab line before change
+LABEL=/                 /                       ext3    defaults        1 1
+#sample /etc/fstab line after noatime change
+LABEL=/                 /                       ext3    defaults ,noatime       1 1
+</code>
+===== Kernel Network Tuning =====
+Add the follwing to /etc/sysctl.conf
+<code>
+#increase local ports
+net.ipv4.ip_local_port_range = 1024 65535
+#reduce the number of time_wait connections
+#these 3 lines can reduce your time_wait count by several hundred percent.
+#however you should not use the following lines in a NATed configuration.
+net.ipv4.tcp_tw_reuse = 1
+net.ipv4.tcp_tw_recycle = 1
+net.ipv4.tcp_fin_timeout = 30
+</code>
+Then call sysctl to make them active
+<code>
+sysctl -p
+</code>