Ubuntu

USB HDD's erratically unmount or will not mount

Asked by apinunt

I have 3 computers, IBM Thinkpad R40, Compaq Presario A900, HP Pavilion g3685l, all running Ubuntu 9.04, and 10 USB hard drives. All the hard drives work reliably under WinXP but work intermittently in Ubuntu. Sometimes they will not mount, or mount only in one USB socket (3 different computers), sometimes the drive will unmount in the middle of a transfer (3 different computers), rebooting clean doesn't seem to be a help and sometimes no problems at all for a day or two. I refrain from doing anything else when using an external drive for fear of creating a problem, but that too does not seem to help.

Currently I am also curious about the content of /dev which the IBM computer shows sda and its partitions along with an entry for sdb while it is mounted and plugged in which disappears when the usb drive is unmounted. My HP computer shows sda and its partitions, but also has sdb, sdc, sdd, and sde in /dev and mounts or tries to mount using sdf. My Compaq shows sda and its partitions and also has an entry in /dev for sdc and currently will not mount an external drive. As best I can tell only sda should appear in /dev as each system has but one hard drive.

I had hoped reformatting to ext3 would solve the problem, but it doesn't appear to care if the drive is ntfs or ext3. My Kingston memory sticks mount reliably using any usb port.

Is this problem peculiar only to me and my 3 computers, or is anyone else experiencing the same, or has anyone an idea of how to solve the problem?

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Launchpad Janitor (janitor) said : 		#1

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

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apinunt (apinunt) said : 		#2

The bug still remains, but in the meantime I've discovered what I think produces the sdb, sdc, sdd, and sdd entries in /dev to be the 4 memory card slots on the front of the computer.
I continue to only erratically be able to mount USB drives, and have had one of the drives unmount while moving a number of files to it, which appears to have corrupted the drive to the point of making it useless and I am now struggling with trying to determine how to recover the content safely. I have searched in vain for some documentation of how the ext3 file system resides on the disk in hopes that I could access my files without writing to the disk or making any changes which might cause further damage. No one appears to be able to answer any of my questions without using the word "maybe", leaving me indecisive as to what I might try.
Perhaps another 15 days of inactivity will clear the problem?

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Launchpad Janitor (janitor) said : 		#3

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

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apinunt (apinunt) said : 		#4

I'm finding 15 days of inactivity insufficient for a problem to self heal. The more I have tried to use external USB hard drives the more data I have found myself losing. Currently I am only using USB memory sticks which are VFAT formatted with no apparent problems. I now am absolutely fearful of even attempting to mount a USB hard drive.

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zepita (zepita) said : 		#5

I'm having the same issue with a sata2 drive connected to an external enclosure.

Sometimes it works very well with transfer speeds up to 30MiB/s but some other times it keeps unmounting and remounting in an endless loop.
I have ubuntu 9.04 running in an intel chipset board.

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apinunt (apinunt) said : 		#6

I'm a little confused, I just received an email containing the above post, asking if this solved my problem. I fail to understand or see what is being offered as a solution.

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Launchpad Janitor (janitor) said : 		#7

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

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apinunt (apinunt) said : 		#8

The problem remains, I'm still struggling with trying to find a way to recover the data that exists on the corrupted drive.

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Launchpad Janitor (janitor) said : 		#9

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

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apinunt (apinunt) said : 		#10

Nothing done, nothing changes.

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Douglas Moyes (aragorn-stellimare) said : 		#11

I've seen this happen with USB drives that are under powered, or on cheap USB hardware.

If this device has no external power besides a USB port, then you'll want to connect it to an external power supply. Also, it helps to connect the drive directly to the USB header rather than through a hub. Also verify that you're using good USB cables.

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apinunt (apinunt) said : 		#12

Each drive has it's own power brick, and I only connect directly to the USB ports available on the computers. I've tried numerous USB cables, all of which worked when connecting the same drives to a WinXP OS, when the drives were NTFS formatted. The problem continues after purchasing some expensive shielded short USB cables which I hoped might be a fix.
 3 computers, 10 external drives, 10 power bricks, 14 USB cables, 1 OS (Ubuntu 9.04).

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Douglas Moyes (aragorn-stellimare) said : 		#13

Hmm..., it may be a bug in the kernel's usb-storage module for that particular device (or, their device is buggy and they released drivers to compensate for those bugs). You may try upgrading the kernel with the latest kernel sources from kernel.org, or wait for them in the repos.

If this is a bug in the kernel, then you'll probably want to make a note of it to the kernel devs, if it's not yet a known issue. Here is what Kernel.org says about reporting Linux kernel bugs:
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Please see the Kernel Newbies (http://kernelnewbies.org/) website.

There is also a wealth of knowledge on many topics involving Linux at The Linux Documentation Project (http://www.tldp.org)

For finding or reporting bugs, look through the archives for the various Linux mailing lists(http://marc.info/?w=2), and if no specific list seems appropriate, try the browsing the Linux Kernel Mailing List(http://marc.info/?l=linux-kernel&r=1&w=2).
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"sudo lspci -v", and "sudo lsusb -v" are useful to giving devs information regarding your hardware... also, if the device should fail on you, be suer to record the output of the "dmesg" command which can provide clues as to why the device died.

As for shielded cables... they only work if both cases are also shielded (if they're not, it can potentially make matters worse with the shield acting like an antenna).

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