Memory disk "a la mfsroot"?

[Pierre-Luc Drouin]

Matthew Seaman wrote:
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> On 11/02/2010 14:53, Pierre-Luc Drouin wrote:
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>   
>> I would like to know if there is a mount command that allows to create a
>> memory disk that can be initialized from a file. What I am looking for
>> is something like mount_mfs -F, but that does not modify the actual
>> file. I know what I could easily to this by copying the content of the
>> file to the memory disk, but I am looking for a solution that can be
>> configured via fstab.
>>     
>
> Yes.  See mdconfig(8) -- there are examples in there of exactly what you
> want to do.
>
> 	Cheers,
>
> 	Matthew
>
> - -- 
> Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
>                                                   Flat 3
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>   
I might be missing something in the mdconfig man page, but in the 
examples I see they always allow modifications to the backing file. As I 
said I am looking for a solution where the backing file is only read, 
but I want to mount the memory disk in read-write mode. Also, I want 
only the modifications to be kept in the RAM, not the initial files.

Thanks!