Which is what I’ve been occasionally spending some time trying to figure out in the past months. Pre OS3 firmware that one particular USB drive mounted, post OS3 it doesn’t. Best I can tell from the logs is the system for what ever reason treats the drive as read only then fails to mount it. The kern log showing some of this.
2016-02-05T00:26:51.389524-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.117064] hub 2-0:1.0: state 7 ports 1 chg 0000 evt 0002
2016-02-05T00:26:51.389585-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.122623] hub 2-0:1.0: port 1, status 0203, change 0001, 5.0 Gb/s
2016-02-05T00:26:51.521834-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.286111] hub 2-0:1.0: debounce: port 1: total 100ms stable 100ms status 0x203
2016-02-05T00:26:51.641813-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.406162] usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
2016-02-05T00:26:51.662976-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.426495] usb 2-1: skipped 1 descriptor after endpoint
2016-02-05T00:26:51.663047-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.431843] usb 2-1: skipped 1 descriptor after endpoint
2016-02-05T00:26:51.681890-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.437633] usb 2-1: default language 0x0409
2016-02-05T00:26:51.681930-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.442284] usb 2-1: udev 2, busnum 2, minor = 129
2016-02-05T00:26:51.681948-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.447135] usb 2-1: New USB device found, idVendor=0480, idProduct=a006
2016-02-05T00:26:51.681963-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.453884] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
2016-02-05T00:26:51.695442-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.461081] usb 2-1: Product: External USB 3.0
2016-02-05T00:26:51.695479-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.465560] usb 2-1: Manufacturer: Toshiba
2016-02-05T00:26:51.695494-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.469693] usb 2-1: SerialNumber: 2011111316674
2016-02-05T00:26:51.704156-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.474647] usb 2-1: usb_probe_device
2016-02-05T00:26:51.704228-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.478401] usb 2-1: configuration #1 chosen from 1 choice
2016-02-05T00:26:51.715383-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.484096] usb 2-1: Successful Endpoint Configure command
2016-02-05T00:26:51.726630-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.489918] usb 2-1: adding 2-1:1.0 (config #1, interface 0)
2016-02-05T00:26:51.726684-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.495857] usb-storage 2-1:1.0: usb_probe_interface
2016-02-05T00:26:51.732995-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.501443] usb-storage 2-1:1.0: usb_probe_interface - got id
2016-02-05T00:26:51.746704-05:00 di=NqJQ6FTJD8 info kernel:[ 5713.508096] scsi2 : usb-storage 2-1:1.0
2016-02-05T00:26:51.746760-05:00 di=NqJQ6FTJD8 debug kernel:[ 5713.512547] /files/sq_kernel/linux/drivers/usb/core/inode.c: creating file '002'
2016-02-05T00:26:57.007958-05:00 di=NqJQ6FTJD8 notice kernel:[ 5718.772506] scsi 2:0:0:0: Direct-Access TOSHIBA External USB 3.0 0001 PQ: 0 ANSI: 6
2016-02-05T00:26:57.008017-05:00 di=NqJQ6FTJD8 notice kernel:[ 5718.781441] sd 2:0:0:0: Attached scsi generic sg1 type 0
2016-02-05T00:26:57.041742-05:00 di=NqJQ6FTJD8 notice kernel:[ 5718.782426] sd 2:0:0:0: [sdb] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB)
2016-02-05T00:26:57.041825-05:00 di=NqJQ6FTJD8 notice kernel:[ 5718.782789] sd 2:0:0:0: [sdb] Write Protect is off
2016-02-05T00:26:57.041841-05:00 di=NqJQ6FTJD8 debug kernel:[ 5718.782805] sd 2:0:0:0: [sdb] Mode Sense: 33 00 00 08
2016-02-05T00:26:57.041857-05:00 di=NqJQ6FTJD8 notice kernel:[ 5718.783145] sd 2:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
2016-02-05T00:26:57.041869-05:00 di=NqJQ6FTJD8 info kernel:[ 5718.811903] sdb: sdb1
2016-02-05T00:26:57.051870-05:00 di=NqJQ6FTJD8 notice kernel:[ 5718.818534] sd 2:0:0:0: [sdb] Attached SCSI disk
2016-02-05T00:26:59.457978-05:00 di=NqJQ6FTJD8 crit kernel:[ 5721.221206] ufsd: "mount" (sdb1): RAW NTFS volume: Filesystem size 931.51 Gb > volume size 931.51 Gb. Mount in read-only
2016-02-05T00:26:59.471877-05:00 di=NqJQ6FTJD8 err kernel:[ 5721.234767] ufsd: unable to replay native journal on "sdb1"
2016-02-05T00:26:59.471928-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.240460] ufsd:unload kernel utf8
2016-02-05T00:26:59.471949-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.243982] ufsd:fill_super("sdb1"), 5643790: cc81c980 10000000, force,iocharset=utf8,fmask=000,dmask=000,uid=65534,gid=1000,user_xattr, verbose
2016-02-05T00:26:59.496603-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.257039] ufsd: Pages: total=e2e, free=305, buff=70, shift=16
2016-02-05T00:26:59.496649-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.263017] ufsd: Page flags: lck=1, err=2, ref=4, upt=8, drt=10, wrb=2000, priv=800
2016-02-05T00:26:59.496667-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.270837] ufsd: Buff flags: upt=1, drt=2, lck=4, map=20, new=40, del=200, aread=80, awrite=100
2016-02-05T00:26:59.512008-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.279780] ufsd: "sdb1": size = 0x74705daf*0x200 >= 0xe8e0bb*0x10000
2016-02-05T00:26:59.512064-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.286304] ufsd: "sdb1": no discard
2016-02-05T00:26:59.522818-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.290634] ufsd:
2016-02-05T00:26:59.522859-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.292666] ufsd: ======NTFSBoot->le(0)======
2016-02-05T00:26:59.522874-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.297083] ufsd: Signature : NTFS
2016-02-05T00:26:59.533519-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.301558] ufsd: RWBlocks : 0x74705daf x 0x200, sdb1, rw
2016-02-05T00:26:59.533576-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.307803] ufsd: SectorsPerVolume : 0x74705daf x 0x200
2016-02-05T00:26:59.542933-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.313145] ufsd: SectorsPerCluster : 0x8
2016-02-05T00:26:59.542973-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.317194] ufsd: MFT : 0xc0000
2016-02-05T00:26:59.555487-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.321576] ufsd: MFTMirr : 0x10
2016-02-05T00:26:59.555525-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.325694] ufsd: Record size : -10
2016-02-05T00:26:59.555539-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.329739] ufsd: Index size : 1
2016-02-05T00:26:59.563643-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.333597] ufsd: Magic : 0x55aa
2016-02-05T00:26:59.563680-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.337902] ufsd: ===========================
2016-02-05T00:26:59.575120-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.342287] ufsd: Boot's size of Volume is greater then allowed in RWBlock!!
2016-02-05T00:26:59.575179-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.349423] ufsd: Boot is accepted as NTFS of size 931.51 Gb
2016-02-05T00:26:59.590449-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.355121] ufsd: RAW NTFS volume: Filesystem size 931.51 Gb > volume size 931.51 Gb. Mount in read-only
2016-02-05T00:26:59.590492-05:00 di=NqJQ6FTJD8 crit kernel:[ 5721.364673] ufsd: "mount" (sdb1): RAW NTFS volume: Filesystem size 931.51 Gb > volume size 931.51 Gb. Mount in read-only
2016-02-05T00:26:59.614125-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.376165] ufsd: BdSetBlockSize 1000
2016-02-05T00:26:59.614176-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.379856] ufsd: Loading $Volume...
2016-02-05T00:26:59.614192-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.383860] ufsd: $Volume: 3.1, 0, "Toshiba1T"
2016-02-05T00:26:59.614204-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.388374] ufsd: Loading $LogFile...
2016-02-05T00:26:59.621900-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.392101] ufsd: $LogFile: 4000000 bytes
2016-02-05T00:26:59.621962-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.396184] ufsd: Loading $MFT...
2016-02-05T00:26:59.636618-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.399541] ufsd: MFT: used=33e0,total=33e0
2016-02-05T00:26:59.636666-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.405590] ufsd: End of journal read. Actions 0. empty
2016-02-05T00:26:59.636701-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.410904] ufsd: Native journal is not empty!
2016-02-05T00:26:59.646761-05:00 di=NqJQ6FTJD8 err kernel:[ 5721.415387] ufsd: unable to replay native journal on "sdb1"
2016-02-05T00:26:59.646801-05:00 di=NqJQ6FTJD8 notice kernel:[ 5721.421018] ufsd:fill_super failed to mount sdb1: "" ->-22
From the wdnas.log file:
2016-02-05T00:26:53.064567-05:00 di=NqJQ6FTJD8 info logger: INFO: Device added: device=3, vendor=Toshiba, model=External USB 3.0, serial_number=2011111316674, revision=0.01
2016-02-05T00:26:59.157253-05:00 di=NqJQ6FTJD8 info logger: INFO: attached USB partition, reduce inotify limit to: 20000
2016-02-05T00:26:59.777577-05:00 di=NqJQ6FTJD8 err logger: ERR: wdAutoMountLib: mount -t ufsd -o force,iocharset=utf8,fmask=000,dmask=000,uid=nobody,gid=share,user_xattr /dev/sdb1 /var/media/Toshiba1T, status 8192