feyrer@cs.stevens.edu (Hubert Feyrer) writes:

> 	sd0: drive offline

This means the device doesn't understand one or the other
command to query size or layout or that such a command returns
invalid data.

>umass0: umass_bbb_transfer cmd=0x12
>umass0: CBW 43: cmdlen=12 (0x12000000240000000000...), data = 36 bytes, dir = in

This is an INQUIRY command.

>umass0: Handling BBB state 1 (BBB CBW), xfer=0xc0a88600, NORMAL_COMPLETION
>umass0: Handling BBB state 2 (BBB Data), xfer=0xc0a88900, TIMEOUT
>umass0: BBB_DATA actlen=0
>umass0: Data-in 36 failed, TIMEOUT

Which fails.

Now I'm confused. How can 'sd0' try to attach when the initial
inquiry already fails?

You want USB_DEBUG and SCSIPI_DEBUG in the kernel and set umassdebug
to something reasonable (the bits are in umassvar.h).

-- 
-- 
                                Michael van Elst
Internet: mlelstv@serpens.de
                                "A potential Snark may lurk in every tree."