On Apr 6, 2019, at 11:08 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx<mailto:stern@xxxxxxxxxxxxxxxxxxx>> wrote: Can you provide the "lsusb -v" output for the storage device as shown on both computers? I want to see if the server and the client disagree on the maxpacket sizes for the bulk endpoints. The key is that 3584 is a multiple of 512 but not of 1024. Sorry for the delay. Physical device: Bus 006 Device 006: ID 13fe:5500 Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.10 bDeviceClass 0 bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 9 idVendor 0x13fe idProduct 0x5500 bcdDevice 1.00 iManufacturer 1 iProduct 2 USB DISK 3.0 iSerial 3 070192D930D6C811 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 44 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 504mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 8 bInterfaceSubClass 6 bInterfaceProtocol 80 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 3 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 3 Binary Object Store Descriptor: bLength 5 bDescriptorType 15 wTotalLength 22 bNumDeviceCaps 2 USB 2.0 Extension Device Capability: bLength 7 bDescriptorType 16 bDevCapabilityType 2 bmAttributes 0x00000006 BESL Link Power Management (LPM) Supported SuperSpeed USB Device Capability: bLength 10 bDescriptorType 16 bDevCapabilityType 3 bmAttributes 0x00 wSpeedsSupported 0x000e Device can operate at Full Speed (12Mbps) Device can operate at High Speed (480Mbps) Device can operate at SuperSpeed (5Gbps) bFunctionalitySupport 2 Lowest fully-functional device speed is High Speed (480Mbps) bU1DevExitLat 10 micro seconds bU2DevExitLat 2047 micro seconds can't get debug descriptor: Resource temporarily unavailable Device Status: 0x000c (Bus Powered) U1 Enabled U2 Enabled Virtual Device: Bus 004 Device 019: ID 13fe:5500 Kingston Technology Company Inc. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 9 idVendor 0x13fe Kingston Technology Company Inc. idProduct 0x5500 bcdDevice 1.00 iManufacturer 1 iProduct 2 USB DISK 3.0 iSerial 3 070192D930D6C811 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 44 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 126mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 8 Mass Storage bInterfaceSubClass 6 SCSI bInterfaceProtocol 80 Bulk-Only iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 3 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 3 Binary Object Store Descriptor: bLength 5 bDescriptorType 15 wTotalLength 22 bNumDeviceCaps 2 USB 2.0 Extension Device Capability: bLength 7 bDescriptorType 16 bDevCapabilityType 2 bmAttributes 0x00000006 Link Power Management (LPM) Supported SuperSpeed USB Device Capability: bLength 10 bDescriptorType 16 bDevCapabilityType 3 bmAttributes 0x00 wSpeedsSupported 0x000e Device can operate at Full Speed (12Mbps) Device can operate at High Speed (480Mbps) Device can operate at SuperSpeed (5Gbps) bFunctionalitySupport 2 Lowest fully-functional device speed is High Speed (480Mbps) bU1DevExitLat 10 micro seconds bU2DevExitLat 2047 micro seconds Device Status: 0x000c (Bus Powered) U1 Enabled U2 Enabled Seth