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Sorry for the delay responding to this thread. Whilst linux users' |
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computers are immune to viruses, our bodies are not. I spent Tuesday |
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evening through late Wednesday afternoon in bed with the flu, and I'm |
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still not 100%. |
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|
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On Tue, Apr 18, 2006 at 10:51:44AM +0800, Fr?d?ric Grosshans wrote |
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> Le lundi 17 avril 2006 ? 18:51 +0100, Konstantin V. Gavrilenko a ?crit : |
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> > |
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> > So you have to do fdisk /dev/sdb, then quit, then the /dev/sdb1 is |
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> > magically available for mounting. |
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> |
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> I had this problem before, but it's not the case today :-( |
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> fdisk has no access to the /dev/sda device. |
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|
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Frederic and Konstantin... |
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|
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I have *EXACTLY* the same situation, and I figured out what was |
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causing it, and I came up with with a workaround; I wouldn't call it a |
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perfect solution. |
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|
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- My old, emergency backup machine is a 1999 Dell PIII, 450 mhz, with |
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128 megs of RAM, and USB 1.1 hardware. According to dmesg, the |
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ehci_hcd code aborts at bootup, and only the ohci_hcd code runs. |
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All my USB1 and USB2 devices run OK. Mind you, at USB 1.1 speeds, |
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maybe I should say they *CRAWL* OK. The "auto" option for filesystem |
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type works OK in both the "mount" command and in /etc/fstab. I |
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could get away with an fstab entry like... |
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/dev/sdb1 /mnt/external auto noauto,user,noatime,notail 0 0 |
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and simply "mount /mnt/external", regardless of what I hooked up to |
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the USB port. |
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|
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- My relatively new AMD64 (in 32-bit mode) has USB2 hardware. I built |
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both ohci_ocd ehci_ocd into the kernel. I experienced the following |
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symptoms... |
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|
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- USB1 devices were totally flakey, sometimes they would show up as |
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/dev/sdb1, and sometimes they wouldn't. When it didin't show up... |
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> > So you have to do fdisk /dev/sdb, then quit, then the /dev/sdb1 is |
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> > magically available for mounting. |
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would usually work, but not always. |
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|
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- USB2 devices would show up OK, and run at USB2 speeds, but "auto" |
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would *NOT* work as a filesystem type with either /etc/fstab or the |
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"mount" command |
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|
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After a lot of screwing around I came up with the following workaround. |
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- build ohci_hcd into the kernel |
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- build ehci_hcd as a module. Do *NOT* auto-load the ehci_hcd module. |
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- write local udev rules to generate symlinks for my USB devices. |
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/etc/fstab has entries that mount the symlinks, and those entries |
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specify the filesystem type. I use "msdos" for my camera's memory |
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cards, "vfat" for my mp3 player, and "reiserfs" for my backup drives. |
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|
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Run in USB1.1 mode most of the time. When I'm backing up my hard |
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drive to a USB2 drive, and I want the extra speed, I run the commands |
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modprobe ehci_ocd |
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udevstart |
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|
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...before I plug in the backup drive. When I'm finished, and have removed |
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the backup drive, I run the commands |
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rmmod ehci_ocd |
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udevstart |
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|
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...and I'm back to where I was before. It's not perfect, but it works. |
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|
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-- |
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Walter Dnes <waltdnes@××××××××.org> In linux /sbin/init is Job #1 |
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My musings on technology and security at http://tech_sec.blog.ca |
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-- |
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