On 07/08/2016 05:52 PM, Mike Christie wrote: > On 07/07/2016 04:21 PM, Xose Vazquez Perez wrote: >> Is "ID_UID" really valid? >> >> libmultipath/hwtable.c: .uid_attribute = "ID_UID", >> > > I was wondering the same thing. For ceph rbd, we do not have the normal > scsi serial/wwn values, so I am modifying our udev rule to export ID_UID. > > I made the ID_UID, the values we use for the udev (/dev/rbd) name which > is the pool name (basically just a grouping of storage) plus the image > name (basically name of a disk created in a pool). ID_UID isn't "standard". It wasn't found in kernel, multipath-tools or systemd(udev) sources. It's variable returned by dasdinfo from 390-tools package, it contains the "DASD uid" of a dasd device. And it's used by udev rules to make symlinks for dasd devices under /dev/disk/by-id/ This is hercules, but in a LPAR shows a similar output: sles11-s390x:~ # dasdinfo -e -a -d /dev/dasda ID_BUS=ccw ID_TYPE=disk ID_UID=HRC.ZZ000000000001.0120.22 ID_XUID=HRC.ZZ000000000001.0120.22 ID_SERIAL=0X0122 sles11-s390x:~ # grep ID_UID /etc/udev/rules.d/59-dasd.rules KERNEL=="dasd*[!0-9]", ENV{ID_UID}=="?*", SYMLINK+="disk/by-id/$env{ID_BUS}-$env{ID_UID}" KERNEL=="dasd*[0-9]", ENV{ID_UID}=="?*", SYMLINK+="disk/by-id/$env{ID_BUS}-$env{ID_UID}-part%n" It was used for dasd devices in multipath-tools because they haven't a WWN. So, invent another undocumented variable name :-) , "ID_CEPH" or "ID_CEPH-RBD" ... -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel