how to boot or access problem file system

PJ af.gourmet at
Thu Jul 30 19:45:48 UTC 2009

Michael Powell wrote:
> PJ wrote:
>> What can be done to access a file system that seems to have the boot
>> sector screwed up?
> Usually there are more than 1 file system present. The MBR will have no 
> bearing on any other than the one you need to boot from, and this is usually 
> the "/" - aka "root". Having a screwed up MBR will only prevent a boot and 
> generally shouldn't change or cause any corruption to the other file 
> systems. Caveat being what occurred that produced the situation in the first 
> place.
> Look in here for a list of .iso files:
> There are the boot-only and a livefs images available. The boot-only would 
> be used for a network installation. What you want is the livefs image. 
> Download and burn to a CD.
>> The /usr files should be ok but how to access?
> Boot from the LiveFS CD. There will be a very basic minimum system present 
> that contains some tools which may be useful. Once booted you should be able 
> to mount the problematic file systems from the hard disk and possibly make 
> repairs. It is probably best to utilize the same version as the OS you are 
> trying to repair.
>> I get errors that the file system is full and I have no idea of how to
>> deal with the boot up - the help message is no help!
> It may be that you need to locate something you can delete so that the file 
> system is now "un-full". 
>> Boot says it cannot find a kernel... surely there must be some kind of
>> recovery process even if nothing has been backed up. 
> There are recovery processes available, but mostly this involves a 
> knowledgeable sysadmin and not some magic bullet automated software. This 
> skill requires an in-depth understanding of how the OS functions, and this 
> can take a while to learn. Along with making some mistakes along the way to 
> have something with which to "practice" on.   :-)
>> Surely FreeBSD must
>> be have something that functions like certain software does on MS ?
> Why would FreeBSD be concerned with being like $MS? Going down this path is 
> a waste of time. Forget the $MS and learn the FreeBSD. The learning curve is 
> initially very steep if all you've ever known is $MS, but if you plug away 
> at it you will at some point crest the hill and have a "light bulb goes on" 
> moment where all of the sudden a lot of disparate material solidifies into 
> something cohesive.  
>> I don't have a problem with irrecoverable files, I would just finally
>> understand how things work and what can be done on FBSD.
>> TIA.
>> PJ
> Not knowing more details can lead to dangerous advice in this kind of 
> situation. It may be something as simple as boot0cfg -B -d 0 is all you 
> need. Blindly giving and following such advice without knowing all the 
> circumstances may quickly escalate into disaster. An example would be 
> something like you are triple booting 3 different OS's with Grub and us not 
> knowing that.
> You should probably read the man pages for fdisk, disklabel, and boot0cfg 
> and see/learn what particular command will extricate you from the situation 
> you are presently  more familiar with than us. Get it wrong and it will only 
> get worse. But there are at least 3 ways present in those docs alone which 
> can be used to write out a new MBR.
> -Mike
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I am not particularly interested in becoming a guru on FreeBSD. I just
want to be able to use it productively... by that I do not mean make
money, but get something achieved in the way of programming stuff for my
own website etc. Having to "go back to school" to understand all the
stuff about FBSD is a bit overkill.
The real problem is that the instructions for upgrading and updating
trip all over themselves and confuse the shit out of most of us who are
not FBSD experts. Funny, that there are so many posts and wueries on
google to fix things on FreeBSD. I found one that was very clear and the
upgrade worked...
yet there is something wrong with the upgrade since I cannot get X to
recognize a puny little mouse. And consequently I have no idea if
Firefox is working or if flashplayer is working or acroread9 or anything
for that matter. And there are no explanations that are readily evident
on what to use, when, how and where to use the different programs line
the linux emulation... there are several and then there are sever
flavors of flshplayer (flashplayer9, linux-f8-flashplayer9, and a couple
more relating to linux f10 - those ridiculous descriptions about the
ports are leally a waste of time - why not just say do some heavy
research before using any of this stuff....

I do appreciate the help you are offering as well as all the other guys
who take time out to help us.
It sounds, from what you are telling me, like it may be possible to do
something with my problem computer... will try.
Thanks again.

Hervé Kempf: "Pour sauver la planète, sortez du capitalisme."
Phil Jourdan --- pj at

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