Created attachment 23085 [details] dmesg output, plugging in the drive and running hdparm on it The USB drive includes: ID 04b4:6830 Cypress Semiconductor Corp. CY7C68300A EZ-USB AT2 USB 2.0 to ATA/ATAPI scsi 2:0:0:0: Direct-Access WDC WD25 00BEVE-00WZT0 PQ: 0 ANSI: 0 I encountered this issue once the Ubuntu kernels switched to building ums_cypress as a module, and not including it in the initrd. If the module is not there, the USB device is found: [ 1200.104015] usb 1-8: new high speed USB device using ehci_hcd and address 3 [ 1200.237017] usb 1-8: configuration #1 chosen from 1 choice and cat /sys/bus/usb/devices/1-8/product gives "USB2.0 Storage Device" but I do not get the [ 1200.278612] scsi7 : SCSI emulation for USB Mass Storage devices [ 1200.278930] usb-storage: device found at 3 [ 1200.278934] usb-storage: waiting for device to settle before scanning which I would get with the module loaded. AFAICS from the module description, it should not be needed for normal disk access, only for tools like hdparm or smartctl. I reported also in another bug https://bugs.launchpad.net/bugs/428469 that hdparm hangs 15 seconds when I run it on this disk. If this is unrelated I can file another bug here on it. This is the "resets" message at the end of the attached dmesg log.
Then build in that module, that's the correct thing to do. If ubuntu has an incorrect kernel configuration, take it up with them :)
Thanks for your comment. Well, is it the correct thing to do if the description says this? config USB_STORAGE_CYPRESS_ATACB tristate "SAT emulation on Cypress USB/ATA Bridge with ATACB" depends on USB_STORAGE ---help--- Say Y here if you want to use SAT (ata pass through) on devices based on the Cypress USB/ATA bridge supporting ATACB. This will allow you to use tools to tune and monitor your drive (like hdparm or smartctl). If you say no here your device will still work with the standard usb mass storage class. If this driver is compiled as a module, it will be named ums-cypress. At least the description of the modules is wrong then. Or some things don't work as the authors intended, which could be a bug.