[dm-devel] DM_snapshot_cow filesystem (dmsetup create snapshot)

[Douglas McClendon]

On 12/01/2011 02:20 PM, Alasdair G Kergon wrote:
> On Thu, Dec 01, 2011 at 02:18:37PM -0600, Douglas McClendon wrote:
>> The overlay device in this situation is a read-write tmpfile in tmpfs,
>> looped to be available as the dm-snapshot 'snapshot/overlay device'.
>
> Ah - well if your base device is already read-only, then there is no
> corruption and you should be able to edit the bit of the disk image
> that says 'this image is invalid' and recover it read-only or extend it.

Can I get a commandline that summarizes how to do that 'edit'?

-dmc