# USB Hdd errors and Kernel Problems

## kongl03

I seem to be haivng trouble with my usb harddisk. In Gnome it freezes up and unmounts the disk at random.

Dmesg shows

```

Unable to handle kernel NULL pointer dereference at 00000000000002c0 RIP:

<ffffffff80364192>{bus_reset+66}

PGD 36570067 PUD 3649d067 PMD 0

Oops: 0000 [2]

CPU 0

Modules linked in: ppp_mppe_mppc vmnet vmmon snd_mixer_oss snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_intel8x0 snd_ac97_codec visor usbserial nvnet nvidia tuner bttv video_buf firmware_class btcx_risc tveeprom

Pid: 15884, comm: scsi_eh_20 Tainted: P      2.6.11-gentoo-r10

RIP: 0010:[<ffffffff80364192>] <ffffffff80364192>{bus_reset+66}

RSP: 0018:ffff810039cb9e68  EFLAGS: 00010246

RAX: 0000000000010100 RBX: ffff810024837a00 RCX: ffff81003b3bd130

RDX: 0000000000002003 RSI: 0000000000000000 RDI: 0000000000000100

RBP: 00000000fffffff0 R08: 0000000000000000 R09: 0000000000000001

R10: 00000000ffffffff R11: 0000000000000000 R12: 00000000000002e0

R13: ffff8100317ec800 R14: ffff81003b3bd130 R15: ffff810039cb9ee8

FS:  00002aaaab48cb80(0000) GS:ffffffff80632940(0000) knlGS:00000000556cc6c0

CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b

CR2: 00000000000002c0 CR3: 000000003648d000 CR4: 00000000000006e0

Process scsi_eh_20 (pid: 15884, threadinfo ffff810039cb8000, task ffff81002f191190)

Stack: ffff81003b3bd100 0000000000000000 00000000000002e0 ffffffff80320d17

       0000000000000286 0000000000000000 0000000000000000 ffffffff80321b53

       ffff8100317ec858 06ff81002f191190

Call Trace:<ffffffff80320d17>{scsi_try_bus_reset+71} <ffffffff80321b53>{scsi_error_handler+1267}

       <ffffffff80131077>{do_exit+2615} <ffffffff8010dc6b>{child_rip+8}

       <ffffffff80321660>{scsi_error_handler+0} <ffffffff8010dc63>{child_rip+0}

Code: 48 8b 87 c0 01 00 00 80 78 04 01 75 31 48 8b 73 20 e8 78 72

RIP <ffffffff80364192>{bus_reset+66} RSP <ffff810039cb9e68>

CR2: 00000000000002c0

```

----------

## fctk

did you read this: http://www.gentoo.org/doc/en/usb-guide.xml ?

----------

## kongl03

Yeah I did. Thanks but I should have clarified, I've had this disk working perfectly for close to a year now, but as of late its been acting all strange. Tested it on a Mac and in Windows too I think it could be a hardware error but I'm kinda surprised I'm getting kernel errors. I have got a udev rule defined for it and linux picks up the hdd but on occasion it has trouble reading and writing to it.

----------

## fctk

mhh... check with: http://gentoo-wiki.com/HOWTO_Monitor_your_hard_disk(s)_with_smartmontools

----------

