On Mon, 2006-04-03 at 23:23 +0200, Christophe Varoqui wrote: > Eddie Williams a écrit : > > I see it is kpartx that is defaulting to the 'p' as the delimiter (in > > the set_delimiter function) when the uuid ends with a digit and no > > delimiter when the uuid ends with a character. > > > > Wouldn't it be better to always use the same delimiter by default? As > > it stands now one will not be able to determine that a node is a > > partition versus a full device by just looking at the name. > > > > > This behaviour mimics the kernel partition naming policies : /dev/sd? > partitions have no separator, while /dev/cciss/c0d0 have one, for example. Yes and no. Yes, for /dev/sd nodes it never adds a separator and for /dev/cciss it always adds one. But "no" in the sense that I can not think of any examples prior to this where sometimes it does and sometimes it doesn't (add a separator) for the same device type. The key item here is that it was consistent. For each device you knew what to expect. That made for a nice easy regular expression to figure out what kind of device you were dealing with. For the case of "uuid" nodes I do not see a way to use a regular expression to determine what kind of node you are dealing with. If you have a node that ends with something like "c1" you can not tell if that is partition 1 or the full device. Yes, there are tools available to figure out if a node is a partition or the full disk. I have to admit to being lazy and like the ease at being able at a glance to tell what the node represents. The same work I do not want to have to do as a human I also do not want to have to add to my programs. I often find being lazy makes for good programming. Accomplishing a task with minimal work is always best (and even better if you find someone else has done the work for you). > > kpartx once meant to be a true alternative to in-kernel partition > handling, thus cared about that naming compatibility. > > I'm inclined to leave it that way, if not only to discourage people to > partition multipathed devices :) I can understand that, I was a bit disappointed when I found that kpartx existed. I was not expecting to support partitions on multipath devices. The cat is out of the bag now and I doubt it will go back in. Partitions are here to stay. I started to suggest that I could add a way, perhaps in multipath.conf, to define a default separator. That way someone could override the default behavior fairly easily. I am not sure making this change now is worth it though. I will just accept that I probably need to run 'dmsetup info' on a node to figure out if it is a partition or disk. Thanks Eddie -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
