Re: DM_snapshot_cow filesystem (dmsetup create snapshot)
|[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]|
On 11/27/2011 04:31 PM, Frederick Grose wrote:
On Sat, Oct 29, 2011 at 4:49 PM, Alasdair G Kergon <agk@xxxxxxxxxx <mailto:agk@xxxxxxxxxx>> wrote: markmc did some code that shows how to read the format a few years ago here: http://people.gnome.org/~markmc/code/merge-dm-snapshot.c <http://people.gnome.org/%7Emarkmc/code/merge-dm-snapshot.c> Otherwise look at dm-snap-persistent.c in the kernel tree. Alasdair Users can easily exhaust a LiveUSB snapshot overlay by writing too many changes to the OS filesystem, such as by performing a yum update. Would such an 'exhausted' overlay be amenable to some sort of data recovery or forensics? If so, how so; if not, why not?
Can you not mount the exhausted dm snapshot? If you mean data recovery or forensics beyond that, please elaborate.
I know I've had issues 'read-only' mounting ext3(2?3?4?) filesystems before (on actually read-only block devices). Maybe some flags that I've forgotten get past that, but worst case you can always fake a writable device with a 2nd overlay/snapshot going to a writable device, i.e. if you wanted to let fsck repair things.
-dmc -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel