[OT] Understanding Linux backup limitations

[Bart Silverstrim]

Brian McKee wrote:
> On Fri, Sep 12, 2008 at 4:04 PM, Young <tuxman at knology.net> wrote:
>> Oh, great guru, please hear my plea. :)
>>
>> I want to understand why a Linux partition must be unmounted before a
>> cloned image can be created. I haven't been able to find anything yet; I
>> guess I don't know the key word to search.
>>
>> I'd appreciate a lead to something that explains this limitation.
>>
>> First, I'd like to know if it's a kernel issue, or a file system issue.
>> Then an explanation of why the problem exists.
> 
> I agree with Bart that the only issue is the darned file might change
> while you're backing it up.
> That's not a Linux thing, it's a computer thing.
> 
> LVM can do 'snapshots' that helps overcome this.  I think Windows
> shadow copy is similar.  ZFS has something too.

For the OP, is there a specific situation you're investigating backing 
up for? Anything in particular you're looking for advice on? Or was it 
just curiosity?