Am 26.04.2016 um 18:19 schrieb Henk Slager:
> It looks like a JMS567 + SATA port multipliers behaind it are used in
> this drivebay. The command lsusb -v could show that. So your HW
> setup is like JBOD, not RAID.
Here is the output of lsusb -v:
Bus 003 Device 004: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 44
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
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 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 15
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 15
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 0x00000002
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 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered
> IMHO, using such a setup for software RAID (like btrfs RAID1)
> fundamentally violates the concept of RAID (redundant array of
> independent disks). It depends on where you define the system border
> of the (independent) disks.
> If it is at:
>
> A) the 4 (or 3 disk in this case) SATA+power interfaces inside the drivebay or
>
> B) inside the PC's chipset.
>
> In case A) there is a shared removable link (USB) inside the
> filesystem processing machine.
> In case B) the disks aren't really independent as they share a
> removable link (and as proven by the (un)plug of 1 device affecting
> all others).
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