sysinstall creates corrupt filesystems after repartitioning

[Eric Anderson]

On 03/02/07 08:37, Steven Hartland wrote:
> Eric Anderson wrote:
>> On 03/02/07 07:46, Steven Hartland wrote:
>> Mounting an NFS share on top of a skimmed down /usr is very common,
>> and very desirable.  You may mount /usr from a small read-only
>> partition (vnode file, etc) and then mount a different partition or
>> NFS over it if you detect the one you want.
>>
>> I think this comes down to: if it hurts, stop doing it.  :)
>>
>> Maybe sysinstall should warn you that you are double mounting, but I
>> don't want it to stop letting me do it.
> 
> Interesting if that's a valid thing to do why does everything
> break when its done? Is it ment to be doing a union hence you get
> the combined contents of both? If so its not working correctly in
> this case :( Can you provide me with more info on how this is
> supposed to work eric please.


No, it won't do a union unless you use union.  Things break because you 
mounted an empty /usr on top of a working /usr.  That just breaks 
things, because you probably need binaries in /usr.

The OS doesn't know whether you want to mount an empty fs on a populated 
one, or what.  It does exactly what you ask it to do, and in this case, 
it was a bad thing.

Think of a thin client that has just enough stuff in /usr to make it 
boot and run a few tools.  Then, depending on a startup option, it 
mounts a more populated /usr from NFS (or even a local disk, doesn't 
really matter) over the previous /usr.

The fact is this:  you made a new partition, called it /usr, and told 
sysinstall to mount it.  It did.  That happened to be a problem for you, 
which I could imagine it would be.   Now, I'm not claiming this is the 
cause of your file system corruption issues.  I'm just saying the 
duplicate mount is not a bug, it's a feature.

Eric