[Jfs-discussion] Issuing a 'reboot -n' caused moderate consequences

[Chris T. <web...@sh...>]

Hello All,

This is more of an information post than a true bug report, but may be useful 
for list archiving and general discussion.  I received a technical support 
call from a customer using one of our AMD64 based servers running SharkLinux. 
The installed versions of the software are:

BASESYS = SharkOS 1.06-RC1-AMD64
KERNEL = 2.6.5
JFSUTILS = 1.1.5

Problem 1:
-------------------
Customer issued a 'reboot -n' on the command line during runlevel 3. Following 
the reboot, GRUB informed the user of  
err 3: Bad or corrupt data while decompressing file

Determination:
-------------------
GRUB encountered a problem while trying to decompress the kernel image file.

Steps Taken:
-------------------
- Boot from a repair CD.
- run 'fsck.jfs /dev/sda1' the affected volume
- FSCK reported that the filesystem had problems and they were repaired.
- reboot


Problem 2:
-------------------
Problem 2 is a direct spawn from problem 1. Following repair of the volume, 
GRUB reported: err 5 : File not found

Determination:
-------------------
The kernel image is missing. The kernel was corrupted and removed during the 
fsck process.

Steps Taken:
-------------------
- Boot from a repair CD
- mount the target system's boot and root filesystems.
- chroot into the base system
- reinstall the kernel from /usr/src/linux
- update /boot/grub.conf
- reboot

Final Analysis:
-------------------
The command issued by the customer: reboot -n  =   Don't sync before reboot or 
halt. As such the system went down without properly syncronizing portions of 
the data in memory with the filesystem. The kernel being the last item to be 
unloaded must have been corrupted somewhere in the process.  fsck found and 
removed the corrupted file(s), including the vmlinuz  file. Recommended to 
customer to not use the -n switch when rebooting. Customer explained they 
mistook the switch for the 'now' timespec used when issuing the 'shutdown' 
command.


-- 
Chris Tusa

Linisys, Computing Evolution
ct...@li...
504.464.4610 x1
- Shark Linux Software
- Linux Hardware Products
- Consulting