ceph-deploy disk list doesnt always list all disks

[ceph_deploy.osd][DEBUG ] Listing disks on titan1...                                                                            │···········································································································
[titan1][DEBUG ] find the location of an executable                                                                             │···········································································································
[titan1][INFO  ] Running command: sudo /usr/sbin/ceph-disk list                                                                 │···········································································································
[titan1][DEBUG ] /dev/sda :                                                                                                     │···········································································································
[titan1][DEBUG ]  /dev/sda1 other, ext4, mounted on /                                                                           │···········································································································
[titan1][DEBUG ]  /dev/sda2 swap, swap                                                                                          │···········································································································
[titan1][DEBUG ] /dev/sdb other, unknown                                                                                        │···········································································································
[titan1][DEBUG ] /dev/sdc other, unknown                                                                                        │···········································································································
[titan1][DEBUG ] /dev/sdd other, unknown                                                                                        │···········································································································
[titan1][DEBUG ] /dev/sde other, unknown                                                                                        │···········································································································
[titan1][DEBUG ] /dev/sdf other, unknown                                                                                        │···········································································································
[titan1][DEBUG ] /dev/sdg :                                                                                                     │···········································································································
[titan1][DEBUG ]  /dev/sdg1 ceph data, active, cluster ceph, osd.3, journal /dev/sdg2                                           │···········································································································
[titan1][DEBUG ]  /dev/sdg2 ceph journal, for /dev/sdg1                                                                         │···········································································································
[titan1][DEBUG ] /dev/sdh other, unknown                                                                                        │···········································································································
[titan1][DEBUG ] /dev/sdi :                                                                                                     │···········································································································
[titan1][DEBUG ]  /dev/sdi1 ceph data, active, cluster ceph, osd.0, journal /dev/sdi2                                           │···········································································································
[titan1][DEBUG ]  /dev/sdi2 ceph journal, for /dev/sdi1                                                                         │···········································································································
[titan1][DEBUG ] /dev/sdj :                                                                                                     │···········································································································
[titan1][DEBUG ]  /dev/sdj1 ceph data, active, cluster ceph, osd.5, journal /dev/sdj2                                           │···········································································································
[titan1][DEBUG ]  /dev/sdj2 ceph journal, for /dev/sdj1                                                                         │···········································································································
[titan1][DEBUG ] /dev/sdk :                                                                                                     │···········································································································
[titan1][DEBUG ]  /dev/sdk1 ceph data, active, cluster ceph, osd.6, journal /dev/sdk2                                           │···········································································································
[titan1][DEBUG ]  /dev/sdk2 ceph journal, for /dev/sdk1                                                                         │···········································································································
[titan1][DEBUG ] /dev/sdl :                                                                                                     │···········································································································
ceph@cephadmin:~$ ceph-deploy osd create --zap-disk titan1:sdb