Gentoo Archives: gentoo-user

From: Walter Dnes <waltdnes@××××××××.org>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] No /dev/sda1 with Klingston usb disk. Wrong lsusb output.
Date: Fri, 21 Apr 2006 05:26:36
Message-Id: 20060421052150.GA24847@waltdnes.org
In Reply to: Re: [gentoo-user] No /dev/sda1 with Klingston usb disk. Wrong lsusb output. by "Frédéric Grosshans"
1 Sorry for the delay responding to this thread. Whilst linux users'
2 computers are immune to viruses, our bodies are not. I spent Tuesday
3 evening through late Wednesday afternoon in bed with the flu, and I'm
4 still not 100%.
5
6 On Tue, Apr 18, 2006 at 10:51:44AM +0800, Fr?d?ric Grosshans wrote
7 > Le lundi 17 avril 2006 ? 18:51 +0100, Konstantin V. Gavrilenko a ?crit :
8 > >
9 > > So you have to do fdisk /dev/sdb, then quit, then the /dev/sdb1 is
10 > > magically available for mounting.
11 >
12 > I had this problem before, but it's not the case today :-(
13 > fdisk has no access to the /dev/sda device.
14
15 Frederic and Konstantin...
16
17 I have *EXACTLY* the same situation, and I figured out what was
18 causing it, and I came up with with a workaround; I wouldn't call it a
19 perfect solution.
20
21 - My old, emergency backup machine is a 1999 Dell PIII, 450 mhz, with
22 128 megs of RAM, and USB 1.1 hardware. According to dmesg, the
23 ehci_hcd code aborts at bootup, and only the ohci_hcd code runs.
24 All my USB1 and USB2 devices run OK. Mind you, at USB 1.1 speeds,
25 maybe I should say they *CRAWL* OK. The "auto" option for filesystem
26 type works OK in both the "mount" command and in /etc/fstab. I
27 could get away with an fstab entry like...
28 /dev/sdb1 /mnt/external auto noauto,user,noatime,notail 0 0
29 and simply "mount /mnt/external", regardless of what I hooked up to
30 the USB port.
31
32 - My relatively new AMD64 (in 32-bit mode) has USB2 hardware. I built
33 both ohci_ocd ehci_ocd into the kernel. I experienced the following
34 symptoms...
35
36 - USB1 devices were totally flakey, sometimes they would show up as
37 /dev/sdb1, and sometimes they wouldn't. When it didin't show up...
38 > > So you have to do fdisk /dev/sdb, then quit, then the /dev/sdb1 is
39 > > magically available for mounting.
40 would usually work, but not always.
41
42 - USB2 devices would show up OK, and run at USB2 speeds, but "auto"
43 would *NOT* work as a filesystem type with either /etc/fstab or the
44 "mount" command
45
46 After a lot of screwing around I came up with the following workaround.
47 - build ohci_hcd into the kernel
48 - build ehci_hcd as a module. Do *NOT* auto-load the ehci_hcd module.
49 - write local udev rules to generate symlinks for my USB devices.
50 /etc/fstab has entries that mount the symlinks, and those entries
51 specify the filesystem type. I use "msdos" for my camera's memory
52 cards, "vfat" for my mp3 player, and "reiserfs" for my backup drives.
53
54 Run in USB1.1 mode most of the time. When I'm backing up my hard
55 drive to a USB2 drive, and I want the extra speed, I run the commands
56 modprobe ehci_ocd
57 udevstart
58
59 ...before I plug in the backup drive. When I'm finished, and have removed
60 the backup drive, I run the commands
61 rmmod ehci_ocd
62 udevstart
63
64 ...and I'm back to where I was before. It's not perfect, but it works.
65
66 --
67 Walter Dnes <waltdnes@××××××××.org> In linux /sbin/init is Job #1
68 My musings on technology and security at http://tech_sec.blog.ca
69 --
70 gentoo-user@g.o mailing list