Centos-optimization
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.
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 up a bit, we can apply the changes mentioned above, but also scheduler can be changed in the following way:
# echo deadline > /sys/block/sdc/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.
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`