Re: [Libvir] [for discussion only] virDomainBlockPeek preliminary implementation

On Tue, Oct 16, 2007 at 03:42:50PM +0100, Richard W.M. Jones wrote: > The attached patch (for discussion only) adds a virDomainBlockPeek call, > allowing callers to peek into the block devices of domains. > > +/** > + * virDomainBlockPeek: > + * @dom: pointer to the domain object > + * @path: path to the block device > + * @offset: offset within block device > + * @size: size to read > + * @buffer: return buffer (must be at least size bytes) > + * > + * This function allows you to read the contents of a domain's > + * disk device. > + * > + * Typical uses for this are to determine if the domain has > + * written a Master Boot Record (indicating that the domain > + * has completed installation), or to try to work out the state > + * of the domain's filesystems. IMHO, if we had storage management APIs this use case could be better handled by simply having a piece of metadata associated with the volume. eg, you could just run virVolumeDumpXML() and look for an element <parttable type='mbr'/> Lack of such an element would indicate it was not partitioned. It could also return 'gpt' for the new fangled EFI bios partitioning scheme, or whatever format BSD/Solaris/Sun uses. This would avoid

the ned for every application caller to repeat the magic for sniffing partition table types.