4G memory is supported for Fedora9 running on ThinkPadT61

Environment: Lenovo lenovothinkpadt61withAHCISATA, 4 GBMemory, Fedora9. symptom: Check/proc/meminfo. Only 3 GB memory analysis is found: fedora9 is not configured with PAE in the kernel used for default installation (no PAE can be seen from the config-2.6.25-14.fc9.i686) countermeasure: There is a kernel-PAE-2.6.2 in the Fedora9 installation disk

Environment: lenovo thinkpad t61 with ahci sata, 4 GB Memory, Fedora 9.

Symptom: Check/proc/meminfo and find that only 3 GB memory is available.

Analysis: PAE is not configured in the kernel used during default installation of Fedora 9 (you can see no PAE from the config-2.6.25-14.fc9.i686)

Countermeasure: the Fedora 9 installation disk has a kernel-PAE-2.6.25-14.fc9.i686.rpm package containing the kernel supporting PAE, install it; or compile a self-built kernel supporting PAE, turn CONFIG_HIGHMEM64G and CONFIG_X86_PAE on. After using the new kernel, check/proc/meminfo again and you will see that the memory is already 4 GB. That's good!

Episode:

I originally figure simple direct rpm-ivh kernel-PAE-2.6.25-14.fc9.i686.rpm & reboot, restarted only to find grub can not go! So you 'd better reinstall grub before reboot, otherwise it will be too much trouble.

The installation method is simple: grub-install/dev/sda. I installed it on the SATA hard drive's Master Boot Record MBR;

It can also be installed on linux partitions: grub-instal/dev/sda2, dd if =/dev/sda2 of =/mnt/winxp/Fedora 9.bin bs = 512 count = 1, modify boot. ini, add a line C: \ Fedora 9.bin= "Fedora 9", so that you can start Fedora 9 using the xp Startup menu.

Let's talk about how I saved it:

First, enter the bios, change the SATA mode from AHCI to compatiable (otherwise, the phone dos boot disk does not recognize the hard disk in AHCI mode), and then start the system with the dos boot disk, run the fdisk/mbr command to clear grub on the MBR. Then, xp can be started.

Next, use Fedora 9 to install the disk. After the disk is started to the graphic interface, open the console and mount the original linux root partition to a temporary directory. Then, run grub-install/dev/sda, an error is prompted. The device cannot be found. It is not appropriate. It is reasonable to say no problem! Reluctantly quit chroot. Copy the boot directory in the original root partition to the root directory of the startup system, and run grub-install/dev/sda again. Then, the grub startup interface appears again, hoho.

Restart, enter xp, no problem, go to Fedora 9, always report an error, the error cannot be mounted in the root partition, what is going on? After a long time, I could not solve this problem. I tried both the original kernel and the PAE kernel. After thinking for a long time, I think it may be related to the AHCI interface specification of the hard disk. I enter the bios, change the SATA mode back to AHCI, and enter Fedora 9 again. Everything is OK. It seems that the problem still lies in AHCI.