Но побочные эффекты таки существуют.
Если вы любитель кроссвордов и ребусов, предлагаю маленькую задачку -
найдите "десять" отличий в трёх выводах:
usb-hdd, usb-flash в usb-портах передней панели:
# hwinfo --usb
04: SCSI 900.0: 10600 Disk
[Created at block.245]
Unique ID: R_O4.wf7pBGJN_7A
SysFS ID: /class/block/sdc
SysFS BusID: 9:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-6/2-6:1.0/host9/target9:0:0/9:0:0:0
Hardware Class: disk
Model: "Kingston DataTraveler 2.0"
Vendor: usb 0x0951 "Kingston"
Device: usb 0x1608 "DataTraveler 2.0"
Revision: "PMAP"
Serial ID: "5B8618000034"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdc (/dev/sg3)
Device Files: /dev/sdc, /dev/disk/by-id/usb-Kingston_DataTraveler_2.0_5B8618000034-0:0, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:6:1.0-scsi-0:0:0:0, /dev/disk/by-label/Simply\x20Linux\x206.0.1\x20\x20\x28Flounder\x29
Device Number: block 8:32-8:47 (char 21:3)
Geometry (Logical): CHS 1019/124/62
Size: 7839744 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v0951p1608d0110dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
05: SCSI a00.0: 10600 Disk
[Created at block.245]
Unique ID: +rmv.Okutv2i0fu8
SysFS ID: /class/block/sdd
SysFS BusID: 10:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-5/2-5:1.0/host10/target10:0:0/10:0:0:0
Hardware Class: disk
Model: "StoreJet Transcend"
Vendor: usb 0x152d "StoreJet"
Device: usb 0x2509 "Transcend"
Serial ID: "801130168383"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdd (/dev/sg4)
Device Files: /dev/sdd, /dev/disk/by-id/ata-TOSHIBA_MK5065GSX_10MIC05OT, /dev/disk/by-id/scsi-SStoreJetTranscend, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:5:1.0-scsi-0:0:0:0, /dev/disk/by-id/wwn-0x5000039243b85ee9
Device Number: block 8:48-8:63 (char 21:4)
Geometry (Logical): CHS 60801/255/63
Size: 976773120 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v152Dp2509d0100dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
...
Дополнительно подключен сканер спецификации USB 1.1:
# hwinfo --usb
04: SCSI 900.0: 10600 Disk
[Created at block.245]
Unique ID: R_O4.wf7pBGJN_7A
SysFS ID: /class/block/sdc
SysFS BusID: 9:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-6/2-6:1.0/host9/target9:0:0/9:0:0:0
Hardware Class: disk
Model: "Kingston DataTraveler 2.0"
Vendor: usb 0x0951 "Kingston"
Device: usb 0x1608 "DataTraveler 2.0"
Revision: "PMAP"
Serial ID: "5B8618000034"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdc (/dev/sg3)
Device Files: /dev/sdc, /dev/disk/by-id/usb-Kingston_DataTraveler_2.0_5B8618000034-0:0, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:6:1.0-scsi-0:0:0:0, /dev/disk/by-label/Simply\x20Linux\x206.0.1\x20\x20\x28Flounder\x29
Device Number: block 8:32-8:47 (char 21:3)
Geometry (Logical): CHS 1019/124/62
Size: 7839744 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v0951p1608d0110dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
05: SCSI b00.0: 10600 Disk
[Created at block.245]
Unique ID: datd.Okutv2i0fu8
SysFS ID: /class/block/sdd
SysFS BusID: 11:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.2/usb7/7-1/7-1:1.0/host11/target11:0:0/11:0:0:0
Hardware Class: disk
Model: "StoreJet Transcend"
Vendor: usb 0x152d "StoreJet"
Device: usb 0x2509 "Transcend"
Serial ID: "801130168383"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdd (/dev/sg4)
Device Files: /dev/sdd, /dev/disk/by-id/ata-TOSHIBA_MK5065GSX_10MIC05OT, /dev/disk/by-id/scsi-SStoreJetTranscend, /dev/disk/by-path/pci-0000:00:1d.2-usb-0:1:1.0-scsi-0:0:0:0, /dev/disk/by-id/wwn-0x5000039243b85ee9
Device Number: block 8:48-8:63 (char 21:4)
Geometry (Logical): CHS 60801/255/63
Size: 976773120 sectors a 512 bytes
Speed: 12 Mbps
Module Alias: "usb:v152Dp2509d0100dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
...
15: USB 00.0: 10c00 Scanner
[Created at usb.122]
Unique ID: wn1q.jMD4qdZ1wT8
Parent ID: 2XnU.v+N+B0xY+P6
SysFS ID: /devices/pci0000:00/0000:00:1d.0/usb5/5-2/5-2:1.0
SysFS BusID: 5-2:1.0
Hardware Class: scanner
Model: "Mustek 1200 UB"
Hotplug: USB
Vendor: usb 0x055f "Mustek"
Device: usb 0x0006 "1200 UB"
Revision: "1.00"
Speed: 12 Mbps
Module Alias: "usb:v055Fp0006d0100dc00dsc00dp00ic00isc00ip00"
Config Status: cfg=new, avail=yes, need=no, active=unknown
Attached to: #10 (Hub)
usb-scanner подключен, usb-hdd и usb-flash переподключены к портам передней панели:
# hwinfo --usb
04: SCSI d00.0: 10600 Disk
[Created at block.245]
Unique ID: +rmv.Okutv2i0fu8
SysFS ID: /class/block/sdc
SysFS BusID: 13:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-5/2-5:1.0/host13/target13:0:0/13:0:0:0
Hardware Class: disk
Model: "StoreJet Transcend"
Vendor: usb 0x152d "StoreJet"
Device: usb 0x2509 "Transcend"
Serial ID: "801130168383"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdc (/dev/sg3)
Device Files: /dev/sdc, /dev/disk/by-id/ata-TOSHIBA_MK5065GSX_10MIC05OT, /dev/disk/by-id/scsi-SStoreJetTranscend, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:5:1.0-scsi-0:0:0:0, /dev/disk/by-id/wwn-0x5000039243b85ee9
Device Number: block 8:32-8:47 (char 21:3)
Geometry (Logical): CHS 60801/255/63
Size: 976773120 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v152Dp2509d0100dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
05: SCSI e00.0: 10600 Disk
[Created at block.245]
Unique ID: R_O4.wf7pBGJN_7A
SysFS ID: /class/block/sdd
SysFS BusID: 14:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-6/2-6:1.0/host14/target14:0:0/14:0:0:0
Hardware Class: disk
Model: "Kingston DataTraveler 2.0"
Vendor: usb 0x0951 "Kingston"
Device: usb 0x1608 "DataTraveler 2.0"
Revision: "PMAP"
Serial ID: "5B8618000034"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdd (/dev/sg4)
Device Files: /dev/sdd, /dev/disk/by-id/usb-Kingston_DataTraveler_2.0_5B8618000034-0:0, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:6:1.0-scsi-0:0:0:0, /dev/disk/by-label/Simply\x20Linux\x206.0.1\x20\x20\x28Flounder\x29
Device Number: block 8:48-8:63 (char 21:4)
Geometry (Logical): CHS 1019/124/62
Size: 7839744 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v0951p1608d0110dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
...
15: USB 00.0: 10c00 Scanner
[Created at usb.122]
Unique ID: wn1q.jMD4qdZ1wT8
Parent ID: 2XnU.v+N+B0xY+P6
SysFS ID: /devices/pci0000:00/0000:00:1d.0/usb5/5-2/5-2:1.0
SysFS BusID: 5-2:1.0
Hardware Class: scanner
Model: "Mustek 1200 UB"
Hotplug: USB
Vendor: usb 0x055f "Mustek"
Device: usb 0x0006 "1200 UB"
Revision: "1.00"
Speed: 12 Mbps
Module Alias: "usb:v055Fp0006d0100dc00dsc00dp00ic00isc00ip00"
Config Status: cfg=new, avail=yes, need=no, active=unknown
Attached to: #10 (Hub)
Но даже при подключении двух USB 2.0 носителей к портам задней панели без подключения USB-устройств 1.1, они могут правильно "сесть":
# hwinfo --usb
04: SCSI 2800.0: 10600 Disk
[Created at block.245]
Unique ID: 7bWa.Okutv2i0fu8
SysFS ID: /class/block/sdc
SysFS BusID: 40:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-3/2-3:1.0/host40/target40:0:0/40:0:0:0
Hardware Class: disk
Model: "StoreJet Transcend"
Vendor: usb 0x152d "StoreJet"
Device: usb 0x2509 "Transcend"
Serial ID: "801130168383"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdc (/dev/sg3)
Device Files: /dev/sdc, /dev/disk/by-id/ata-TOSHIBA_MK5065GSX_10MIC05OT, /dev/disk/by-id/scsi-SStoreJetTranscend, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:3:1.0-scsi-0:0:0:0, /dev/disk/by-id/wwn-0x5000039243b85ee9
Device Number: block 8:32-8:47 (char 21:3)
Geometry (Logical): CHS 60801/255/63
Size: 976773120 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v152Dp2509d0100dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
05: SCSI 2900.0: 10600 Disk
[Created at block.245]
Unique ID: FKGF.wf7pBGJN_7A
SysFS ID: /class/block/sdd
SysFS BusID: 41:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.0/host41/target41:0:0/41:0:0:0
Hardware Class: disk
Model: "Kingston DataTraveler 2.0"
Vendor: usb 0x0951 "Kingston"
Device: usb 0x1608 "DataTraveler 2.0"
Revision: "PMAP"
Serial ID: "5B8618000034"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdd (/dev/sg4)
Device Files: /dev/sdd, /dev/disk/by-id/usb-Kingston_DataTraveler_2.0_5B8618000034-0:0, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:1:1.0-scsi-0:0:0:0, /dev/disk/by-label/Simply\x20Linux\x206.0.1\x20\x20\x28Flounder\x29
Device Number: block 8:48-8:63 (char 21:4)
Geometry (Logical): CHS 1019/124/62
Size: 7839744 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v0951p1608d0110dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
...
А могут и нет:
# hwinfo --usb
04: SCSI 2a00.0: 10600 Disk
[Created at block.245]
Unique ID: hSuP.Okutv2i0fu8
SysFS ID: /class/block/sdc
SysFS BusID: 42:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-2/2-2:1.0/host42/target42:0:0/42:0:0:0
Hardware Class: disk
Model: "StoreJet Transcend"
Vendor: usb 0x152d "StoreJet"
Device: usb 0x2509 "Transcend"
Serial ID: "801130168383"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdc (/dev/sg3)
Device Files: /dev/sdc, /dev/disk/by-id/ata-TOSHIBA_MK5065GSX_10MIC05OT, /dev/disk/by-id/scsi-SStoreJetTranscend, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:2:1.0-scsi-0:0:0:0, /dev/disk/by-id/wwn-0x5000039243b85ee9
Device Number: block 8:32-8:47 (char 21:3)
Geometry (Logical): CHS 60801/255/63
Size: 976773120 sectors a 512 bytes
Speed: 480 Mbps
Module Alias: "usb:v152Dp2509d0100dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
05: SCSI 2c00.0: 10600 Disk
[Created at block.245]
Unique ID: UfPf.wf7pBGJN_7A
SysFS ID: /class/block/sdd
SysFS BusID: 44:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:1d.0/usb5/5-1/5-1:1.0/host44/target44:0:0/44:0:0:0
Hardware Class: disk
Model: "Kingston DataTraveler 2.0"
Vendor: usb 0x0951 "Kingston"
Device: usb 0x1608 "DataTraveler 2.0"
Revision: "PMAP"
Serial ID: "5B8618000034"
Driver: "usb-storage", "sd"
Driver Modules: "usb_storage"
Device File: /dev/sdd (/dev/sg4)
Device Files: /dev/sdd, /dev/disk/by-id/usb-Kingston_DataTraveler_2.0_5B8618000034-0:0, /dev/disk/by-path/pci-0000:00:1d.0-usb-0:1:1.0-scsi-0:0:0:0, /dev/disk/by-label/Simply\x20Linux\x206.0.1\x20\x20\x28Flounder\x29
Device Number: block 8:48-8:63 (char 21:4)
Geometry (Logical): CHS 1019/124/62
Size: 7839744 sectors a 512 bytes
Speed: 12 Mbps
Module Alias: "usb:v0951p1608d0110dc00dsc00dp00ic08isc06ip50"
Driver Info #0:
Driver Status: usb_libusual is active
Driver Activation Cmd: "modprobe usb_libusual"
Config Status: cfg=new, avail=yes, need=no, active=unknown
...
Причём последовательность подключения носителей не имеет значения.
Мне понадобилось минут 40 (ну где-то так, или больше? Или часов?, - счёт времени потерял) постоянных plug/unplug чтобы ещё раз повторно воспроизвести эту ситуацию.
Но периодичность её повторения как замечено, м.б. от минимума до бесконечной непредсказуемости.
В любом случае, подключив пару usb-носителей к портам, не поленитесь сделать
# hwinfo --usb
Если результат будет повторяемым, можно будет как-то обобщать и делать какие-то выводы.
Но на основании одного теста на одном ядре, говорить что-то преждевременно.
PS
Приаттачил файл с теми же выводами, но в полном варианте, если кто-то захочет копнуть глубже.
По грубым прикидкам, чтобы словить это, ушло 4-5 часов.
ЗЫж:
... Жаль, что отнял у сообщества столько времени...
Не будь ваша занудливость (в хорошем смысле слова) столь настойчивой, ни за что не взялся бы за тест и не словил бы.
Хлопотное это дело, отнимает много времени с абсолютно непредсказуемым результатом.