The -skip-zeros argument makes the command skip regions of zeros, 16 bytes or more, in the output file.
The command will fail if the destination file already exists, unless -overwrite is specified.
Due to the flexible mapping support in memory-spaces, it can take a long time to save large memory areas. The image variant of the command is much faster, assuming it is used with -skip-zeros.
When used on an image object, the -dirty-only argument can be used to save dirty pages only, i.e. pages which have not been written to one of the image backing files.
The non-namespace version of the command uses the specified object, defaulting to the current frontend processor's physical memory space.