Comment # 3 on bug 954138 from Oliver Neukum

2015-11-08T10:38:35.599324+01:00 veles kernel: [   69.705465] usbcore:
registered new interface driver usb-storage
2015-11-08T10:38:35.600315+01:00 veles kernel: [   69.706792] scsi6 : uas
2015-11-08T10:38:35.601310+01:00 veles kernel: [   69.707206] scsi 6:0:0:0:
Direct-Access     Seagate  Expansion Desk   0909 PQ: 0 ANSI: 6
2015-11-08T10:38:35.601320+01:00 veles kernel: [   69.707894] sd 6:0:0:0:
Attached scsi generic sg3 type 0
2015-11-08T10:38:40.019887+01:00 veles PackageKit: daemon quit
2015-11-08T10:38:41.730335+01:00 veles kernel: [   75.841149] sd 6:0:0:0:
uas_eh_abort_handler ffff8804473ba4c0 tag 1, inflight: CMD IN
2015-11-08T10:38:43.623437+01:00 veles kernel: [   77.736815] sd 6:0:0:0: Bogus
IU (4) received on status pipe

This must not happen. The device gives a strange answer, which prevents
detection of the partition table.
You cannot just blacklist the module. You need to set the 'u' quirk as a
parameter for the device. Please do that to test whether the device works with
the old storage driver.