CentOS optimizations

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In order to speedup the disk management, some values are added to each ext3 partition on the terminal. The reference site is located at CentOS HowTos - Disk Optimizations

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


Don't write access time


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


Set the time to sync data and metadata.

Solid State Disk

Usually the IDE SSD are slower that the SATA SSD, and some times could even be slower than the regular IDE. To speed them up a bit, we can apply the changes mentioned above, but also the scheduler can be changed in the following way:

# echo deadline > /sys/block/sda/queue/scheduler
# echo 1 > /sys/block/sda/queue/iosched/fifo_batch

All the other options for the scheduler can be displayed with the command

# cat /sys/block/sda/queue/scheduler

but usually noop and deadline are the 2 that works well with SDD.

To make permanent this change, add the parameter elevator=deadline at the end of the kernel line in /boot/menu/grub.conf


In /etc/sysctl.conf set the vualue

kernel.shmmax = 63554432

to increase Maximum shared segment.


Reduce boot time passing the known values to the kernel, the site that references. Optimizations can be found at Free Electrons - 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
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


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


When reboots, the firmware will be skipped.


Doesn't log all the boot messages to the stdout