GRUB shell on arch linux

My previous post mentioned how to boot from a rootfs shell. From what I am experiencing, I screwed up the grub configuration, so when I boot my computer I am entered directly into a grub shell. To get into the rootfs shell so I can boot arch linux ,I issue the following:


grub> kernel=/vmlinuz-linux [ENTER]
[Linux-bzImage, setup=0x4200, size=0x2fc90]
grub> initrd=/initramfs-linux.img [ENTER]
{Linux-initrd @ 0x7fd35000, 0x2ba04e bytes]
grub> boot [ENTER]


It then proceeds to boot the kernel. I am aware that it's taking me to rootfs because I'm not entering the device. I just haven't toyed with it enough, or bothered searching for the appropriate values. /dev/sda and /dev/sdaX do not work. I will update whenever I figure it out.

UPDATE:

I found out what was causing this. The entry in grub (which I have now agonizingly updated to grub2) was set to look for the device /dev/disk/by-uuid/c48c81b7-e772-42a6-95af-f27d768b887b
looking in /dev/disk/by-uuid, that uuid did not exist, nor was it the one for /dev/sda4
I changed it to the corresponding uuid and what it was linked to.

Here is a sample output from my laptop:

# ls -l /dev/disk/by-uuid

lrwxrwxrwx 1 root root 10 Mar 29 14:46 1c7fe2bc-2f14-48e4-84b7-08f1c53a90e2 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Mar 29 14:46 492b94e8-25b4-463b-86a3-6e80d3b40632 -> ../../dm-2
lrwxrwxrwx 1 root root 10 Mar 29 14:46 4c34416c-fc03-4add-b1a0-ba9f5603bc4c -> ../../dm-0
lrwxrwxrwx 1 root root 10 Mar 29 14:46 78b772e4-59b1-4563-b6ab-6d9c24ef9fcd -> ../../sda2
lrwxrwxrwx 1 root root 10 Mar 29 14:46 c3230d94-1048-4c3e-8e35-aea175f6f667 -> ../../dm-1
lrwxrwxrwx 1 root root 10 Mar 29 14:46 f8c7dfa7-907a-4ac5-a2e4-a89e139b7224 -> ../../sdb2


Pretty straightforward, no?

service script on arch linux

Personally I am accustomed to redhat builds of Linux and find myself typing "service".
Instead of typing /etc/rc.d/$service $command where $service is the name of the service I wish to start, or searching for a pre-made solution, I wrote up a little script and saved it as /usr/sbin/service.


#/bin/sh
/etc/rc.d/$1 $2


After saving it chmod it to 755 so it can be executed. You can now issue the command: service network start

and have the network service start successfully, or whichever service script you find in /etc/rc.d

rootfs on arch linux

Find yourself in a bind and logged in to a recovery shell named rootfs?

If you happen to know the partition that your operating system is on, and the boot partition, you can boot into your kernel from this shell.

On my system, I have this layout:

/dev/sda1 > /boot
/dev/sda2 > /home
/dev/sda3 > / (ext4)
/dev/sda4 > / (ext4)


From this rootfs shell, I executed the following commands and booted into the desired kernel on sda4.


# mkdir /boot
# mount -t /dev/sda4 /new_root
# cd /new_root
# exec init


This had me boot into my fresh install of arch that I had installed from another partition. Now I can fix grub!