Archive for May, 2009

12
May
09

Fedora 10 error with SCSI RAID controller

N95-889

While installing Fedora 10 onto machine with SCSI RAID controller, error may come out while booting, as show above.

The machine will forever stucked there without getting into Fedora desktop if only reboot, swap disk, remove RAID setting action are taken.

To solve this problem:

Insert the Fedora 10 installation CD and reboot (force reboot is applicable).

On the GUI page for installation options, select Rescue an Installed System.

Select Do NOT start network devices. Click Continue.

On bash shell prompt, type:

# chroot /mnt/sysimage

# cd /boot

Backup the existing initial ramdisk image first. (Optional but recommended)

For example, the ramdisk image name is initrd-2.6.27.21.170.2.56.fc10.x86_64.img

# mv initrd-2.6.27.21.170.2.56.fc10.x86_64.img initrd-2.6.27.21.170.2.56.fc10.x86_64.img.original

Create a new initial ramdisk image:

# mkinitrd   – -with=scsi_wait_scan initrd-2.6.27.21.170.2.56.fc10.x86_64.img `uname –r`
*Note that it is “- -” double hypen without space; also grave accent/tilte button ( ` ) followed by “uname…”, not single quote( ‘ )

The ramdisk image filename “initrd-2.6.27.21.170.2.56.fc10.x86_64.img” MUST match the initrd file name in /boot/grub/grub.conf

Reboot and problem shall be solved (you may expecting a working login interface).

Reference:

  1. Fedora Forum
  2. Linuxtopis: Fedora 10. Begining the installation.
02
May
09

Removing Li-ion battery from Laptop really helps it life span?

A lot of people have the thinking that removing the battery from the laptop while using AC current will prolong the battery lifespan from being charged over long time. This concept is simply not right because most of the Li-ion has built-in circuit to cut off the charge in order to prevent over-charging, which will permanently damage the battery (normally 4.2V). So if the battery is already fully-charged, it won’t get charged even you leave it attached with the laptop.

The reason to remove the battery from laptop is because of HEAT! Over period of time, the battery will lose its capacity permanently according to its storage capacity and temperature, as refered to the chart below:
capacity-lostSo, an idle fully-charged Li-ion battery at 40 degree celcius will lose 15% more capacity compared to another battery at room temperature.

With a laptop running more at 60 degree celcius (rarely seen), its attached battery will render useless within a year.  In another words, you can choose to attach your battery with your laptop all the time, as long as you remain the laptop is cool enough (bottom cooling pad with fans).

To store fresh/unused battery, it is recommended to charge the battery to 40% instead of 100%, to reduce its capacity lose over time.

Reference: