article deals with what action is to be taken (during a reboot)
after a power failure or an incomplete shutdown of a
Linux system due to any reason. This problem seems to be very
common since many newcomers install Linux and get all the various
softwares/hardwares working under Linux and suddenly one day
the power fails. And there after they are totally clueless as
to what to do ..since they cant even access HOW TO's without
booting into Linux.
This tutorial will most probably help you get out of that problem.
So please read this even if you haven't faced this problem..since
you never know when you may get unlucky.
are a few things that you can try to get Linux back on track..
rebooting, Linux may print a message saying that there is
a problem with the filesystem and it might force a check.
It would do this for all Linux partitions. If the checks
(they generally take around 30-60 seconds..also displays
a rotating indicator) are successful then you are lucky.
Linux should mostly continue booting and you should be back
in business soon. If this is what happens then you may be
under an impression that a direct switch off of a Linux
machine leads to no problems. Please note that you were
just lucky that you got away without any major problems.
rebooting, Linux may not be successful in any of the filesystem
checks. In this case the booting stops abruptly with a message
stating that you should run fsck manually without
a few parameters. Once you reach the bash prompt (#) then
run the fsck command as mentioned (fsck -a -p /dev/hdaX).
The fsck command requires the partition which it has
to check. So if you have installed linux on /dev/hda1
then you have to run fsck as follows : fsck -a -p /dev/hda1
When you run fsck it would mostly find some inode problems
and ask you whether you want to fix them, Select the default
option (yes). It would do so for all the problems
found. Once this is over you can restart the machine using
either "Ctlr+Alt+Del" or "shutdown -r 0",
whichever works. Now this time your Linux machine should
has so happened that once when the power failed, Linux simple
failed to boot on my machine. It gave no errors at all,
but the init process would just not get initiated. It would
find my partitions, mount the ext2 filesystem as read only
and then would simply display a prompt. Even with this prompt
I wasn't able to do a lot. Also I noticed that a few of
the default directories were missing on the native partition.
The only solution that I found to this was to Reinstall
Note : While reinstalling, the best and safest way for
the above problem would be to insert the installation
media (Redhat Linux 6.1 CD). And instead of selecting to
install the OS once again, select to upgrade the existing
installation. This would effectively replace
all the damages areas of the OS and would also retain all
your personal data and configurations in Linux (This should
work in almost all cases).
Hence I would always advice an upgrade to the same version
(If you originally had Redhat Linux 6.1 , insert the CD
and once again select to upgrade to Redhat Linux 6.1 itself).
If the upgrade option doesn't fix the problem, then you
would have to do a reinstall after a reformat of the Linux
one case when Linux refused to boot I noticed that a few
of the main files / directories were missing. I found that
the /sbin directory (which is a very important directory)
wasn't there in the root directory. I performed a search
for this directory and found it to be within another directory.
After some discussion I realised that my friend has accidently
moved this directory within his GUI when he was working
in superuser mode. As long as he was working a few commands
didn't work but he did not bother about finding out why
they didn't work. Once he rebooted his machine the abscence
of this directory hung the booting process. So I suggest
that you never work in superuser mode unless absolutely
necessary. Even within the superuser mode prefer the shell,
since you can hardly ever do anything accidently in the
shell. In my friend's case I simply moved that directory
back within the root directory and Linux booted without
So when you have a properly working Linux machine, do take
the time to have a look at the filesystem and make a mental
note of the directory structure which appears to be pretty
complex to newcomers.
Finally after all this if your Linux machine still doesn't boot,
do mail me the exact messages that you see on the screen, I
shall try to help you out. And also invest in an UPS if affordable.
You wouldn't be reading this page if you had one initially.