08:30 root@delta /etc :)  
 -> udevadm info /dev/main/swap
P: /devices/virtual/block/dm-7
N: dm-7
S: disk/by-id/dm-name-main-swap
S: disk/by-id/dm-uuid-LVM-Wy8pjpX6RWUI2GdTbSrc2UIMtPkUAYDkIWLSk8BehahDfcoSTbtXW8eNIZGtGq1o
S: disk/by-uuid/9f405c34-354a-4be4-8075-ff23bd04915e
S: main/swap
S: mapper/main-swap
E: DEVLINKS=/dev/disk/by-id/dm-name-main-swap /dev/disk/by-id/dm-uuid-LVM-Wy8pjpX6RWUI2GdTbSrc2UIMtPkUAYDkIWLSk8BehahDfcoSTbtXW8eNIZGtGq1o /dev/disk/by-uuid/9f405c34-354a-4be4-8075-ff23bd04915e /dev/main/swap /dev/mapper/main-swap
E: DEVNAME=/dev/dm-7
E: DEVPATH=/devices/virtual/block/dm-7
E: DEVTYPE=disk
E: DM_ACTIVATION=1
E: DM_LV_NAME=swap
E: DM_NAME=main-swap
E: DM_SUSPENDED=0
E: DM_UDEV_DISABLE_LIBRARY_FALLBACK_FLAG=1
E: DM_UDEV_PRIMARY_SOURCE_FLAG=1
E: DM_UDEV_RULES_VSN=2
E: DM_UUID=LVM-Wy8pjpX6RWUI2GdTbSrc2UIMtPkUAYDkIWLSk8BehahDfcoSTbtXW8eNIZGtGq1o
E: DM_VG_NAME=main
E: ID_FS_TYPE=swap
E: ID_FS_USAGE=other
E: ID_FS_UUID=9f405c34-354a-4be4-8075-ff23bd04915e
E: ID_FS_UUID_ENC=9f405c34-354a-4be4-8075-ff23bd04915e
E: ID_FS_VERSION=1
E: MAJOR=254
E: MINOR=7
E: SUBSYSTEM=block
E: TAGS=:systemd:
E: UDISKS_DM_TARGETS_COUNT=1
E: UDISKS_DM_TARGETS_LENGTH=4194304
E: UDISKS_DM_TARGETS_PARAMS=8:2\x202048
E: UDISKS_DM_TARGETS_START=0
E: UDISKS_DM_TARGETS_TYPE=linear
E: UDISKS_PRESENTATION_NOPOLICY=1
E: USEC_INITIALIZED=698709