gistfile1.txt

Take a look at the scsi lines, with 'scsi 11:0:0:0' v.s. scsi 11:0:0:1' - the last 0/1 is the logical unit number.  Hidden volume drive has two LUNs.

Drive w/ hidden volume:

[14448.296921] scsi host11: usb-storage 2-3.4:1.0
[14449.301962] scsi 11:0:0:0: Direct-Access              USB DISK         1.00 PQ: 0 ANSI: 4
[14449.302936] scsi 11:0:0:1: Direct-Access              USB DISK         1.00 PQ: 0 ANSI: 4
[14449.303853] sd 11:0:0:0: Attached scsi generic sg4 type 0
[14449.304387] sd 11:0:0:1: Attached scsi generic sg5 type 0
[14452.632704] sd 11:0:0:1: [sdc] 8392696 512-byte logical blocks: (4.30 GB/4.00 GiB)
[14452.636011] sd 11:0:0:1: [sdc] Write Protect is off
[14452.636022] sd 11:0:0:1: [sdc] Mode Sense: 23 00 00 00
[14452.639275] sd 11:0:0:1: [sdc] No Caching mode page found
[14452.639284] sd 11:0:0:1: [sdc] Assuming drive cache: write through
[14452.643414] sd 11:0:0:0: [sdb] Attached SCSI removable disk
[14452.656100]  sdc:
[14452.665368] sd 11:0:0:1: [sdc] Attached SCSI removable disk


## Drive w/o hidden lun:

[14416.291155] scsi host10: usb-storage 2-3.4:1.0
[14417.314936] scsi 10:0:0:0: Direct-Access                               PMAP PQ: 0 ANSI: 4
[14417.316561] sd 10:0:0:0: Attached scsi generic sg4 type 0
[14418.730072] sd 10:0:0:0: [sdb] 15124992 512-byte logical blocks: (7.74 GB/7.21 GiB)
[14418.730779] sd 10:0:0:0: [sdb] Write Protect is off
[14418.730781] sd 10:0:0:0: [sdb] Mode Sense: 23 00 00 00
[14418.731398] sd 10:0:0:0: [sdb] No Caching mode page found
[14418.731401] sd 10:0:0:0: [sdb] Assuming drive cache: write through
[14418.757025]  sdb: sdb1
[14418.760651] sd 10:0:0:0: [sdb] Attached SCSI removable disk