topic Re: Linux Root Filesystem Read Only in Operating System - Linux

Linux Root Filesystem Read Only

Jason Shannon — Tue, 29 Apr 2008 10:01:18 GMT

I have a Proliant server running Redhat 4. I had to run an up2date on it to bring it to Redhat 4 Update 4. I did that using the ISO's I had downloaded from Red Hat.

The up2date ran fine (no errors or dependency problems) but upon reboot the root filesystem mounted as read only so the boot hung.

I used my rescue cd and edited grub.conf to mount / as rw and it seemed to help it although now when i try to login as root at the prompt i receive 'Permission Denied'.

I'm guessing that editing grub.conf was totally wrong as any other Linux systems I have show / being mounted as ro in this file (must be somewhere else later it mounts it as rw).

Does anybody have any thoughts on this?

Any help greatly appreciated.

Re: Linux Root Filesystem Read Only

skt_skt — Tue, 29 Apr 2008 13:46:49 GMT

Go to rescue mode using the RHEL installation CD with the boot option:

linux rescue

if vg00 not getting mounted automaically.

2.Try to activate the volume groups by running the commands below:

lvmdiskscan
vgchange -ay

3.If vg00 is acitaved Further fsck test can be done using:

tune2fs -l /dev/vg00/lv01 | grep Block

Take note of the Block size.

e2fsck -b -n /dev/vg00/lv01

Also if you encounter any super block corruption then try
# mke2fs -n /dev/vgeb_gdh0_p/lvol10
mke2fs 1.32 (09-Nov-2002)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
131072 inodes, 262144 blocks
13107 blocks (5.00%) reserved for the super user
First data block=0
8 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376

# e2fsck -b 32768 /dev/vgeb_gdh0_p/lvol10
e2fsck 1.32 (09-Nov-2002)
/dev/vgeb_gdh0_p/lvol10 was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/dev/vgeb_gdh0_p/lvol10: ***** FILE SYSTEM WAS MODIFIED *****
/dev/vgeb_gdh0_p/lvol10: 11/131072 files (0.0% non-contiguous), 12329/262144 blocks

Re: Linux Root Filesystem Read Only

Steven E. Protter — Tue, 29 Apr 2008 14:13:52 GMT

Shalom,

The root filesystem has been damaged.

e2fsck is needed.

You should be able to just boot single user and do this, but rescue mode is the standard approach.

SEP

Re: Linux Root Filesystem Read Only

Jason Shannon — Wed, 30 Apr 2008 09:15:54 GMT

Your answers got me going in the right direction - thanks.

The issue was that because we SAN boot with multipath, when the kernel rebuilt as part of the up2date it lost its path to the boot disk (and ended up seeing multiple copies of it).

I zoned down to 1 path, and presented a cloned boot disk copy (i took this before doing any work). After booting up on this disk, I ran up2date again. This time it seems to have gone a lot smoother EXCEPT for the fact that now when i get to the GUI login prompt and try to login as root I receive a pop up saying "Authentication Failed".

Any more help is greatly appreciatted.