Device attached over iscsi not found at /dev/disk/by-path.

The iscsiadm also shows that there are devices without attached disk:

sudo iscsiadm -m session -P 3

iSCSI Transport Class version 2.0-870
version 2.0-873
Target: iqn.2000-08.com.datacore:win2012-2
    Current Portal: 172.17.4.48:3260,1
    Persistent Portal: 172.17.4.48:3260,1
            **********
            Interface:
            **********
            Iface Name: default
            Iface Transport: tcp
            Iface Initiatorname: iqn.1993-08.org.debian:01:873f6f119c4
            Iface IPaddress: 172.17.6.89
            Iface HWaddress: <empty>
            Iface Netdev: <empty>
            SID: 11
            iSCSI Connection State: LOGGED IN
            iSCSI Session State: LOGGED_IN
            Internal iscsid Session State: NO CHANGE
            *********
            Timeouts:
            *********
            Recovery Timeout: 120
            Target Reset Timeout: 30
            LUN Reset Timeout: 30
            Abort Timeout: 15
            *****
            CHAP:
            *****
            username: <empty>
            password: ********
            username_in: <empty>
            password_in: ********
            ************************
            Negotiated iSCSI params:
            ************************
            HeaderDigest: None
            DataDigest: None
            MaxRecvDataSegmentLength: 262144
            MaxXmitDataSegmentLength: 262144
            FirstBurstLength: 0
            MaxBurstLength: 1048576
            ImmediateData: No
            InitialR2T: Yes
            MaxOutstandingR2T: 1
            ************************
            Attached SCSI devices:
            ************************
            Host Number: 19 State: running
            scsi19 Channel 00 Id 0 Lun: 0
                    Attached scsi disk sdcs         State: running
            scsi19 Channel 00 Id 0 Lun: 1
            scsi19 Channel 00 Id 0 Lun: 10
                    Attached scsi disk sdaw         State: running
            scsi19 Channel 00 Id 0 Lun: 11
                    Attached scsi disk sdax         State: running
            scsi19 Channel 00 Id 0 Lun: 12
                    Attached scsi disk sday         State: running
            scsi19 Channel 00 Id 0 Lun: 13
            scsi19 Channel 00 Id 0 Lun: 14
                    Attached scsi disk sdba         State: running

See Lun 1 or Lun 13 for example.