domain mapfile

Hi,

Err, what exactly is a domain mapfile? I've never heard of one before!
At a guess, is it something like the batch imaging you can do with Clonezilla over a network?

Thanks,
Hamish

Oh really? No no, nothing like that. Its the "-m" switch on ddrescue. Its a different type of logfile (renamed mapfile recently I believe), which limits the clone to the areas defined in the domain mapfile.

For example, using ddru_ntfsbitmap (part of ddrutility) this creates a domain mapfile which only contains the used blocks on the NTFS partition. Using this file, in conjunction with a clone, saves a lot of time - as you are not trying to recover any blocks that are not in use.

So the below I would use to create the domain mapfile.

ddru_ntfsbitmap /dev/sda1 /media/sdb1/sda1_domain.log

And then the below (just with the -m switch) to include the domain mapfile.

ddrescue -m /media/sdb1/sda1_domain.log /dev/sda1 /media/sdb1/sda1.img /media/sdb1/sda1_log.log

I'm sure there are a number of other switches that would also be useful for this, but that's all I've been using recently. It can really save a lot of time if you only have say, 200GB worth of data on a 1TB drive.

Hi,

Sounds like a really helpful switch! I'll definitely add that to my list of features to add :)
Do you know if it works with filesystems other than NTFS?
It may be hard to add it without adding a lot of extra code if not, but that doesn't mean I won't do it, because it sounds very useful.

Thanks,
Hamish

Hi,

Yeah as far as I am aware, you can create a domain mapfile for any file system - using the ddru_ntfsbitmap above was just an example for the NTFS file system. Unfortunately I wouldn't know what tools to use for any other file system however. Its just limits the rescue to predifined blocks.

To me I believe you just need to add another option just like the logfile (now mapfile since ddrescue v1.20), to point to an existing domain mapfile.

How users will create these domain mapfiles is anyones guess!

It's great to hear that your going to add this to the list! (:

It'll be very usefull to me. Thank you.

PS. Would it be possible to edit the switches created by ddrescue-gui before you tell it to begin? So lets say I've chosen all the settings I want, but theres a switch you don't have in the GUI that I would like to add; would it be possible to edit the command and then tell it to run?

Hi,

Okay good to know, but if it's new for ddrescue v1.20, I might not be able to add this feature except for OS X and Parted Magic (Ubuntu 12.04, 14.04, 15.04, 15.10 use ddrescue 1.14, 1.17, 1.19, 1.19, I think.), but definitely something to add to the list :)

If possible, the GUI will create the domain maplfile for the user, rather than expecting people to know how to do it (I didn't even know what one was!).

No you can't do that but adding support for something like that in a future release might not be a bad idea either :)

Hamish

Hi,

It's coming up to release time for DDRescue-GUI v1.5, and I've been busy fixing bugs and making big improvements so I didn't find the time to add these features, but just so you know, they're on the agenda for v1.6.

Hamish