Revision as of 08:19, 1 March 2011

CentOS Optimizations

Disk

In order to speedup the disk management, some values are added to each `ext3` partition on the terminal. The reference site is located at [[1]]

 LABEL=/                 /                       ext3    defaults,noatime,data=writeback,commit=120        1 1
 tmpfs                   /dev/shm                tmpfs   defaults        0 0
 devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
 sysfs                   /sys                    sysfs   defaults        0 0
 proc                    /proc                   proc    defaults        0 0
 /customswap swap swap defaults 0 0
 

noatime

Don't write access time

data=writeback

The data order is not preserved when writes to disk. Just after set this value and before restart the terminal run the following command to avoid goes into read-only mode.

 tune2fs -o +journal_data_writeback /dev/hda1
 

commit=120

Set the time to sync data and metadata.

System

In `/etc/sysctl.conf` set the vualue

 kernel.shmmax = 63554432
 

to increase Maximum shared segment.

Boot

Reduce boot time passing the known values to the kernel, the site that references. Optimizations can be found at [[[Media:centos-optimization$embedded_linux_optimizations.pdf|Embedded|Linux Optimizations]]]

 # grub.conf generated by anaconda
 #
 # Note that you do not have to rerun grub after making changes to this file
 # NOTICE:  You do not have a /boot partition.  This means that
 #          all kernel and initrd paths are relative to /, eg.
 #          root (hd0,0)
 #          kernel /boot/vmlinuz-version ro root=/dev/hda1
 #          initrd /boot/initrd-version.img
 #boot=/dev/hda
 default=0
 timeout=0
 splashimage=(hd0,0)/boot/grub/splash.xpm.gz
 hiddenmenu
 password --md5 $1$/omJBwhD$phlKUXHDZI6BMLkNSfNgD/
 title Bashlinux 
     root (hd0,0)
     kernel /boot/vmlinuz-2.6.18-53.el5 ro root=LABEL=/ rhgb vga=792 lpj=998235 reboot=soft quiet
     initrd /boot/initrd-2.6.18-53.el5.img
 

lpj

Loops per jiffy can be obtained from `/var/log/messages`

reboot=soft

When reboots, the firmware will be skipped.

quiet

Doesn't log all the boot messages to the `stdout`