On Tue, Nov 01, 2005 at 02:53:57PM -0800, Patrick Mansfield wrote: > Per posts and an accepted patch on dm-devel about dm multipath user > friendly names: > > https://www.redhat.com/archives/dm-devel/2005-October/msg00004.html > https://www.redhat.com/archives/dm-devel/2005-October/msg00067.html > > But the above is a dm multipath only solution. > > It's a good idea to allow user specified names on top of the > /dev/disk/by-* device names. Though dm likely needs a dm_id in order to > support the method outlined here. > > If we could set and compare environment variables Sure we can do that with ENV. '=' sets, '==' compares. > or compare SYMLINK, How would we compare the list of sysmlinks? True, if on of them matches? > separate rules file (doesn't have to be separate, just seems like a good > idea) could be used to add symlinks to user specified names. All the persistent symlinks are composed from variables still available to match anytime later to add more links. > i.e. move udev_rules.c:apply_format() into udev_utils.c, and call it > before comparison as well as before (AFAIUI) generating names, though I > somehow doubt the change is that simple. > > Then, we could have rules like: > > KERNEL=="sd*[!0-9]|sr*|dasd*[!0-9]", ENV{ID_SERIAL}=="?*", ENV{ID_FULL_PATH}="disk/by-id/$env{ID_BUS}-$env{ID_SERIAL}" > ENV{ID_FULL_PATH}=="?*", SYMLINK+="$env{ID_FULL_PATH}" Hmm, why this indirection? Can't you just use ID_SERIAL and ID_BUS in the second rule again? > And for each device that we want to give a user specified name, use (would > also need partition specific rules): > > ENV{ID_FULL_PATH}=="disk/by-id/scsi-360a98000686f68656c6e7a416f4b6849" SYMLINK+="media-files" > > And similar for the other disk/by-* methods. > > Any comments on the above? > > Is my rule just wrong, or is there a better method? > > Running with udev 069 on FC rawhide, with these rules: > > SYMLINK=="*foo*" SYMLINK+="user/bar" SYMLINK lists can't be matched until now. > KERNEL="sdm" ENV{VAL1}="somevalue" > KERNEL="sdm" ENV{VAL2}="$env{VAL1}" The value does not get expanded at the time you assign it, so the later compare will look like: 'somevalue' == '$env{VAL1}' which does not match. > KERNEL="sdm" SYMLINK+="user/show-val1-$env{VAL1}" > KERNEL="sdm" SYMLINK+="user/show-val2-$env{VAL2}" > > ENV{VAL1}=="somevalue" SYMLINK+="user/val1" > ENV{VAL2}=="somevalue" SYMLINK+="user/val2" > > Do not work as might be expected: since the env values are not expanded, > the last rule never matches, and user/val2 link is never created. The > above generated (sdaz is the last device found): > > [elm3a49 ~]$ ls -l /dev/user > total 0 > lrwxrwxrwx 1 root root 7 Nov 1 14:18 bar -> ../sdaz > lrwxrwxrwx 1 root root 6 Nov 1 14:18 show-val1-somevalue -> ../sdm > lrwxrwxrwx 1 root root 6 Nov 1 14:18 show-val2-somevalue -> ../sdm > lrwxrwxrwx 1 root root 6 Nov 1 14:18 val1 -> ../sdm Thanks, Kay -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
