Improper shutdown of system / Fragmentation Problems / Boot logs

Jerry McAllister jerrymc at clunix.cl.msu.edu
Tue Jun 8 07:36:54 PDT 2004


> 
> I am kinda new to FBSD, still kinda learning stuff. Anyway, when my
> system boots i see all kinda fragmentation information. How do I correct
> this? Any good reading material? 

Do not correct it.   It is not at all the same thing as fragmentation
in Microsloth systems and is not a problem.   There are some papers
on the topic and I seem to remember something written up, maybe on
onlamp.com or somewhere like that, that explain it fairly well.  Do
a little searching on UFS, FFS and fragmentation to accumulate some info.

>   Also, what should I do when I shutdown
> my system incorrectly and boot up again? 

Use the "shutdown"(8) command to shut the system down.
If it goes down improperly, such as in a power failure, generally
the standard fsck(8) during the subsequent boot will take care 
of it.   It is possible that a file or two gets too mangled or
the root file system in unclean and then it will ask you to run fsck
manually.   Generally, then it will dump you right in to single user 
mode, but if not, then boot to single user mode and then run 'fsck -f'
on each file system it can automatically recover starting with root (/)
You may have to do some 'y' responses or if it is so much it is onerrous,
then do  'fsck -fy' and it will assume a 'y' at every point.
Then, when it is all cleaned up, just reboot.   On rare occasions I have
had to do the process twice.  But anything more than that is a strong
indicator that the hard drive itself is the problem and it is failing
and only a replacement will solve the problem.

> Last questions! I promise. Is
> there a file that shows the data printed to screen durning boot?
> Probably, a log file.

The "dmesg"(8) command will normally print out what you need.
If the system has been up too long for it to go back far enough, 
then look in the file:   "/var/run/dmesg.boot"

////jerry

> 
> Thanks guys,
> Bruce
> 


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