On 02/16/2011 04:21 AM, Phillip Susi wrote: > It used to be that partitions device names just had a digit added on to > the base disk device name. It seems that this became problematic at > some point with device mapper and oddly named disks, and there have been > several responses to it: > > 1) dmraid and (lib)parted now always add a 'p' between the base name > and the partition number > > 2) kpartx from multipath-tools adds the 'p' only if the base name ends > in a digit > > 3) Debian and Ubuntu's udev and init scripts tell kpartx to use 'part' > instead of just 'p'. > > 4) gparted now explicitly tells dmraid to not use any character so that > it behaves like older versions and is therefore compatible with the > kpartx method that gparted has adopted, at least when the base name does > not end with a digit. > > Each of these components needs to agree on what the correct name is or > chaos ensues. I would like to discuss the merits of each and try to > decide on a standard. > > Having thought about it for a moment, it seems to me that deciding on > always adding the 'p' is the way to go, since the 'art' just makes > things longer for no good reason, and if you only sometimes add the 'p' > then you can't tell if a device name that ends in a digit that does not > follow a 'p' is a whole disk, or a partition. > No. The linux scheme since the dawn of time is to a) Add the partition number to the device node name b) If last letter of the device node name is a number, insert a 'p' between device node name and partition number with the advent of persistent device names (via udev) the partition separator (for persistent links only!) is '-part'. So you have /dev/sda /dev/sda1 /dev/disk/by-id/scsi-0WhatAStupidName /dev/disk/by-id/scsi-0WhatAStupidName-part1 persistent device names are longish anyway, so we can as well use something readable for partitions. 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
