On Tue, Jan 10, 2017 at 05:06:13PM +0100, Jelle de Jong wrote:
Hello everybody,
I am using libguestfs-tools version 1.28.1 in a bunch of bash scripts to make back-ups of the files on a visualisation platform.
I been trying to get read access to ntfs volumes with data deduplication working.
Do you have more information about data deduplication? It's the first I've heard of it for NTFS (or indeed any ordinary Unix filesystem). In fact I thought it was a feature of the block layer rather than the filesystem. But anyway ...
The ntfs-3g guys developed some support and I have this working when using the commands our back-up servers.
However when using the guestmount tool the read suport foor dedub is gone.
This is maybe not especially surprising. A lot of layers have to work correctly in order for a feature to be passed through guestmount. You've got (at least) kernel+FUSE on the host side (for guestmount), the libguestfs API, the appliance kernel, and ntfs-3g in the appliance. Getting discard support working involved a considerable effort.
See this email for all the commands I use (working mount -t ntfs and non-working guestmount commands).
https://sourceforge.net/p/ntfs-3g/mailman/message/35595392/
How can I see what version of ntfs-3g is used in guestmount and if it is using the /usr/lib/x86_64-linux-gnu/ntfs-3g/ntfs-plugin-80000013.so plugin that is on my back-up server?
Probably helpful to refer to the diagram here: http://libguestfs.org/guestfs-internals.1.html ntfs-3g in your case is running in the "appliance" box in that diagram. The plugin file *should* be copied into the appliance, assuming that it's part of the Debian ntfs-3g package and the Debian ntfs-3g package isn't doing anything weird. You can easily check using virt-rescue: $ virt-rescue --ro -a windows.img
<rescue> ls -l /usr/lib/x86_64-linux-gnu/ntfs-3g/ <rescue> mount /dev/sda1 /sysroot
(and then use whatever ntfs commands are needed to check that the plugin is being used) Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW