I am able to boot and run commands from external USB hdd; the message in question appears for about 45 seconds then booting continues. GRUB2 is installed on internal HDD. When choosing to boot directly to /dev/sdb the message doesn't appear, however boot time is about the same as booting to internal HDD.

 Timing cached reads:   1018 MB in  2.00 seconds = 508.97 MB/sec
 Timing buffered disk reads:  80 MB in  3.03 seconds =  26.37 MB/sec
pfeiffep@de:~$ sudo hdparm -i /dev/sdb

SG_IO: bad/missing sense data, sb[]:  70 00 05 00 00 00 00 10 00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 HDIO_GET_IDENTITY failed: Invalid argument

Gparted correctly identifies the drive as SAMSUNG MP0402H.

Any ideas how to remedy the HDIO & SG_IO messages?

  • This only occurs when I boot Grub2 from internal hard drive and choose to boot OS on USB hard drive. If I choose in BIOS to boot Grub2 on USB hard drive either the message too quickly disappears or doesn't occur.
    – pfeiffep
    Apr 29, 2013 at 11:46

1 Answer 1


This is what some USB mass storage devices return if they have trouble making sense of the data.

I have a lexar 8 in 1 card reader, and on some SDxc cards, while doing the write performance from debian palimpset, the reader just die with that error. and then the card will give that error on that reader forever.

if i put the card on a smarter/less buggy reader, and format, then the lexar reader will read it again without a problem.

i never wasted time to find out what data in the card memory trigger that behaviour. but i'm 100% sure it is data only. maybe the lack of a partition schema? no idea... but aparently, besides the incompatibility of the several SD sub-formats that plague card readers, not we also have to worry about crazy partition formats.

So the cause is: bogus data written to your partition record/boot sector/whatever SD cards have.

solution is to insert card/drive/whatever you are using for memory on another USB mass storage translator device and create a partition there. then your problem is solved.

if it is a monolithic device, i.e. something that has memory chips and the USB mass storage translator on the same board... you have a bigger problem, as there is not easy way to fix that now.

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