My install linux Centos 6.5, 64 bit system is now a read only install. I cannot write to it.

If I try to change it to a read write system using the command:

mount -o remount,rw /dev/hda2 /

(provided I have my root system as /dev/hda2)

it says : mount command not found. It says likewise for remount or umount.

So now I cannot change my hardrive from read only to read write. I am missing at whatever runlevel I am in.

I am root, however.

So my question is how can I change the linux install from read to read write if I am missing the mount, remount commands?

Can this be solved by linux rescue or chroot?

Those are the first two methods thta sprnig to mind.

Any help appreciated. Thanks in advance.

R,



jyunker

You sure that it's not listed as /dev/sda2?

Does that mean it had been working for some time and now you get this message? I doubt that CentOS 6.5 is going to show your drives as hd? rather than sd?. What changes did you make to the system just prior to this? Becoming read only geneerally happens with a problem with the filesystem and you need to run fsck on the system.

Very likely your path doesn't include /bin/mount...

Which usually indicates a problem with your shell environment.

Use mount with the full path.

If you can't mount your root filesystem, first try a fsck from the rescue console, then mount -a; failing that, use a 'live' system to take a look at your disk.

Oaky, I see the problem now. I am in emergency mode in my Centos 6.5, 64 bit system, from what I have read emergency mode is like runlevel 1 except the system install is now read only.

One is very limited in the commands that he can give. I am looking for anything online that tells one how to get out of emergency mode.

So is there a step-by-step process to get out of emergency mode and into runlevel 1. I can take it from there.

Any help appreciated.

Thanks in advance.

I would just use the centos cd & chroot

I would love to use the Centos rescue CD/DVD. I am relieved that I finally found out
what run-level that I am in : emergency mode. I thougt is was in some bott purgatory.

At least that is a start. I need to repopulate the boot directory and the grub subdirectory.

I know in Ubuntu there is a program to do just this, is it compatible with Centos 6.5, 64 bit?

My guess is that it is not.


Respectfully,


jyunker

Your guess is correct. Also, when I installed CentOS 6.5, it was still using Grub Legacy. switched to Grub2 with 7.0. What happened to your boot directory? You should be able to copy the necessary files from the installation medium of CentOS but you would need to modify the grub.conf/menu.lst file to suit your machine or else create a new one.

Is this machine a dual-boot, if not you're mounting the wrong device. It should be /dev/sda1.
Can you run And

This all very new and that is why I am asking these questions.

My last command was

chroot /mnt/sysimage/

which generated no complaints.

Now I would love to run

fdisk -l and any other command.

However, I would like to run them on my /mnt/sysimage/ mounted install and I am not sure how to do that. Also I would like to run any other commands given above.

I just need to know where to do so and how.


Thanks in advance.


R,

jyunker

When I ran fdisk -l

I got

sh: fdisk command not found

and if I ran it again, I got the same thing.

Now when I ran

cat /etc/fstab

I got


#
# /etc/fstab
# Created by anaconda on Thu may 31, 12:55:35 2012
#
# accessible filesystem, by referernce, are manipulated under 'dev/disk'
# see man pages fstab(5), findfs(8), mount(8) and or bik(8) for more info
#
/dev/mapper/vg_james-lv_root / ext4 defaults 1 1
UUID=484051fe-2fd6-43d4-a752-71cd429969f5d /boot ext4 defaults 1 2
/dev/mapper_vg_james-lv_home /home ext4 defaults 1 2
/dev/mapper_vg_james-lv_swap swap swap defaults 0 0
tmpfs /dev/shm tempfs 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



This as best as I can copy it.


R,

jyunker

Are you mounting with live-cd?
What instructions are you following for /mnt/sysimage/?
Have you mounted proc, sys & dev

Changing to read only often happens with a corrupted filesystem and as suggested above, you could try running fsck on whichever partition it is. Why do you think you need to re-populate your boot and grub directories? Have you mounted your boot partition and the files are not there?

I boot up into Centos rescue. I am asked a set of questions about language and keyboard. It asks me if I want to start the network interfaces and I respond - no.

It gives a choice of rescue environments:

Continue Read-Only Skip Advanced

I select continue.

It says it is examining storage devices.


Then it says system has been mounted under
/mnt/sysimage


it also says the

Press return to get a shell. If you want to move your system the root environment, run the command:

chroot /mnt/sysimage.

I select ok.


It then says you system is mounted under the /mnt/sysimage directory. I acknowledge with ok.


It then gives a choice of three items:

shell Start shell
fakd run diagnostic
roboot Reboot


I select start shell and I get choose ok.

I get a shell prompt.

bash-4.1#

I can access my system at the command line. I cd /mnt/sysimage/

It is there - my system.

At this point I issue the command


chroot /mnt/sysimage/

(I assume that it is all that is required since that is all it says to do in the
boot up screens).


I issue the command and after a delay of 1 or 2 seconds it responds:
with a carriage return.

At this point it seems my entire file is now on the regular hard drive as I have known it.

I type (ls) at the coomand prompt and I get a listing of fles and directories.

The mnt directory is there. I cd into it and the sysimage is gone. Only the cdrom directory is there.

I type exit is it puts me back into graphical command mode.


I know that chroot usually has three bind commands (dev,run...). I did not use them.

The graphical interface only shows the one command.


chroot /mnt/sysimage/


I can use the LiveCD that I made, but it seems that simply using the Centos rescue option on the
on my centos 6.5, 64 bit install disk was easier.

I do not want to do anymore harm than necessary.

I have yet to make my Centos install read write from read only, but I will when I am sure of the commands.

I hope this shows acurrately where I am.

Any help appreciated.


R,

jyunker

I know that to run fsck one not mount files. So if I ran fsck i will not select continue

at the prompt and instead select skip.