Power Failure Test Failure

Power Failure Test Failure

Post by racel.. » Wed, 31 Jan 1996 04:00:00



To the Guru's,

I tested how Linux would recover from a power failure by simply turning
off the PC without doing a proper shutdown. It failed miserably. It will
not reboot.

It seems to do fine until it gets to the point where it tries to mount
/ (my /dev/hda3). So, I took out my boot/root disk and
booted with it. Didn't work either, because it also tries to mount
/dev/hda3. So, next I tried booting with the abare/color disk combination
and managed to boot. I then mounted /dev/hda3 unto the /root directory,
just to see if I can still access it. I could, but cannot execute
executable programs.

I then read the Sys Admin guide from LDP, and guessed from the info
that maybe the file system was trashed (for some background, the disk
did have some bad sectors when I first formatted it). It advised me
for such a situation to try and fix it with a utility called e2fsck
which I should find on my boot/root disk. It wasn't and neither was it
on abare/color. So, I proceeded to copy it from /root/sbin (remember
I mounted /dev/hda3 unto /root) to /bin, thinking maybe I can execute it
from there. I couldn't. I can see it with an "ls -l", which seem to
indicate it was executable (rwxr-xr-x), but I can not execute it.

So, please tell me, O Linux Guru:
1. Why did it fail to reboot? Please guess or tell me what details you
   need and how I can get them.
2. How come I can't execute programs I described above? How can I
   execute e2fsck or any other programs from the mounted disk (vi
   especially).
3. Or, here's a thought, how can I reboot without checking the file
   system? I'm guessing that is where it is failing, and I could execute
   e2fsck after it boots (oh, but will e2fsck work on a mounted disk?).


Otherwise, I'll just read it here.

Thanks to all. This group has helped me a lot, and I've also contributed
some. This really is a fast way to learn.

Again, thanks in advance.

Regards,

 
 
 

Power Failure Test Failure

Post by Jim Van Zan » Thu, 01 Feb 1996 04:00:00



>I tested how Linux would recover from a power failure by simply turning
>off the PC without doing a proper shutdown. It failed miserably. It will
>not reboot.

Hmm.  Do you dive into strange swimming holes, too?  :-)

Quote:>I then read the Sys Admin guide from LDP, and guessed from the info
>that maybe the file system was trashed

Unix (and other decent OSs, and even DOS sometimes) doesn't write data
to disk immediately.  If you shut down without flushing disk buffers,
the filesystem can be left in an inconsistent state.

Quote:>...fix it with a utility called e2fsck

right.

Quote:>I can see it with an "ls -l", which seem to
>indicate it was executable (rwxr-xr-x), but I can not execute it.

Two guesses:

1) It's not statically linked, and your diskette doesn't have the
required dynamic libraries.  You will have to find a statically linked
version.  Try looking on other "root" or "emergency" diskettes.

2) It ran, but refused to fix the partition.  You'll have to unmount
the partition first (e.g. "umount /dev/fda2").

Incidently, if you login as a user other than root and mount a
filesystem, you won't be able to execute programs off the filesystem.

                   - Jim Van Zandt

 
 
 

1. power failure vs slow ups battery failure

we sell ups power protection for sun machines so here goes.
1. if your ups has an rs-232 port or dry contacts on the back you can
probably buy off the shelf software for sun. making it work is simple, but
the cable can be a troublesome project.
2. Some of the vendors who make ups shutdown software are Systems
enhancements, APC, upsonics, us, ETI, Etc. All are easy to install, and
give different features. I recommend going with the easiest. Ours for
instance will give a sun script to actually reboot the computer after
power is returned thru the main power.
3. you can also buy extended batteries from most people to get like 12-24
hours of battery protection. but it takes room,
4. i recommend you get the brand name off of your ups, and call the
manufacturer, not the distributor, as it is a small sale to them and most
have no clue as to what they are selling.
5. system enhanc is in St. Louis ?
    upsonics=1800upsonics
    us=8002095556
    apc8008904272
    eti=4195224466

Powerstar Inc.                                                  UNIX
,SCSI, UPS Technologies
Gaithersburg Maryland
800-209-5556
fax 301-948-0715

2. -- VFS: Unable to mount root -- Help!

3. mail help!!!

4. Backup power, power failures, and crashes

5. KDE 2.2.1: kdebindings doesn't compile

6. Power On after power failure not working (Motherboard M787CLR/M787CL)

7. fvwm install problem

8. Promoting switch failures to node failures (HACMP 4.4)

9. cyrus: failure: prot layer failure

10. cyrus: failure: prot layer failure (SuSE 8.2)

11. DMA failure on ASUS, but NOT on Tyan (was PentiumII/440FX PCI DMA failure)

12. Installation/Running GeForce2 Linux EMERGENCY, FAILURE AFTER FAILURE