Thank you . On Sunday, 16 December 2018 15:28:08 IST Greg KH wrote: > On Sun, Dec 16, 2018 at 01:09:48PM +0200, borissh1983@xxxxxxxxx wrote: > > Hi, > > > > I got to a slight confusion about what is the correct way to safely > > disconnect hdd sata over usb adapter with external power unit from > > laptop running Linux (4.18). > > > > my current action list was : > > > > 1. unmount everything > > That's all you need to do. > > You can also issue a "power off" command to the drive now if you want to > shut off the power to it (and the drive/controller actually support it). Not knowing if said drive does or does not support it (hdparam -Y ) made me go to the safest next choice. (sleep) man file says don't do it if you don't know what you are doing (and I'm not). > I know gnome-disks has that option and I use it all the time with my > external sata USB controller. > > > 2. sync > > You could do that before unmount, but unmount will also do that for you. > No need to do this afterward. > Thanks. > > 3. hdpram -S 30 /dev/sdX (I'm not sure if does anything honestly because > > device is connected over a sata to usb interface) > > What does this do? Why "sleep" the drive? > sleep have more chances to be implemented. > > 4. Wait for ~20 minutes > > Huh? Why 20 minutes? > just to play safe. > Just unmount and then power off the device, that should be sufficient. > > good luck! > > greg k-h When I asked this morning , I had one dead drive, this afternoon I got another that looks like a dead one (kernel does not enumerate it or even show a connection ) . I do not see any problem with pata (2.5") over usb (worked with two drives that did not fail yet). The drive that failed , had been the ones with sata connection but not with an IDE connection. When connected over PATA it is identified as Bus 001 Device 029: ID 152d:2338 JMicron Technology Corp. / JMicron USA Technology Corp. JM20337 Hi-Speed USB to SATA & PATA Combo Bridge Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp. idProduct 0x2338 JM20337 Hi-Speed USB to SATA & PATA Combo Bridge bcdDevice 1.00 iManufacturer 1 JMicron iProduct 2 USB to ATA/ATAPI bridge iSerial 5 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 32 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 4 USB Mass Storage bmAttributes 0xc0 Self Powered MaxPower 2mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 8 Mass Storage bInterfaceSubClass 6 SCSI bInterfaceProtocol 80 Bulk-Only iInterface 6 MSC Bulk-Only Transfer Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Device Qualifier (for other device speed): bLength 10 bDescriptorType 6 bcdUSB 2.00 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 bNumConfigurations 1 Device Status: 0x0001 Self Powered for a PATA connection : usb 1-1: new hih-speed USB device number 29 using xhci_hcd usb 1-1: New USB device found, idVendor=152d, idProduct=2338, bcdDevice= 1.00 usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=5 usb 1-1: Product: USB to ATA/ATAPI bridge usb 1-1: Manufacturer: JMicron Sold under the brand name Gold-Touch sata to usb. Either I had two faulty sata hard drives within one week ,two bad adaptors or some nasty luck. Thanks.