Which two statements are true about debugging OCFS2?

Which two statements are true about debugging OCFS2?

A.
The o2imagecommand copiesOCFS2file system data from the device to the specified image file.

B.
The o2imagecommand copiesOCFS2file system metadata from the device to the specified image file.

C.
You must mount the debugfs file system to enable the use of the debugfs.ocfs2 command.

D.
Trace bits has two possible statuses: allow and deny.

E.
You must unmount allocfs2file systems to enable the use of the debugfs.ocfs2 command.

Explanation:

o2image copies the OCFS2 file system meta-data from the device to the specified image-file. This image file contains the file system skeleton that includes the inodes, directory names and file names. It does not include any file data.
This image file can be useful to debug certain problems that are not reproducible otherwise. Like on-disk corruptions. It could also be used to analyse the file system layout in an aging file system with an eye towards improving performance
As the image-file contains a copy of all the meta-data blocks, it can be a large file. By default, it is created in a packed format, in which all meta-data blocks are written back-to-back. With the -r option, the user could choose to have the file in the raw (or sparse) format, in which the blocks are written to the same offset as they are on the device.
debugfs.ocfs2 understands both formats.