On 03/23/2011 06:30 PM, Phillip Susi wrote: > There are different classes of dm devices that different utilities may > or may not care about. Some are intended to represent whole disks ( > dmraid ) that can be partitioned. Some ARE partitions and should > contain filesystems. Still others are used only internally by the tools > ( -real, -cow for lvm, and raid10 subvolumes for dmraid ). I can not > find any good way to differentiate between these types. > And indeed you are right, there is none. > One way of fixing this is to add a new attribute to the device where the > tools creating them can specify a hint about what they are and how they > should be used. Another way is to embed that information in the UUID. > For instance, logical volumes have UUIDs that start with "LVM-" and > dmraid disks start with "DMRAID-". Perhaps dmraid partitions could have > their uuids changed to "DMRAIDP-" and internal devices changed to > "DMRAIDI-" and "LVMI-" for dmraid and lvm respectively. > That is the approach I've been following for SUSE. The UUID is assumed to be of this syntax: <type>-<identifier> where <type> is defined by the program creating the mapping. EG 'mpath' for multipath, 'partX' (where 'X' is the partition number) for kpartx etc. Not that these prefixes are registered in any way; would be nice to have them registered / documented somewhere. Cool would be to have them build into the module :-) Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
