anders
Posts: 6
Joined: Fri Aug 16, 2013 2:09 am

My Pi destroys USB sticks

Wed Sep 18, 2013 5:22 pm

So this has happened to me several times now, so doing another reinstall will probably not help.

After a fresh install (of Arch Linux) I move the root file system to a USB stick. Some normal usage and some restarts later, the Pi will no longer boot. It turns out that the USB stick is no longer recognizable as a drive. Moving root back to SD card and inserting the USB:

Code: Select all

Sep 18 19:08:10 hallonpaj kernel: scsi 3:0:0:0: Direct-Access     Generic  USB Flash Disk   7.76 PQ: 0 ANSI: 2
Sep 18 19:08:10 hallonpaj kernel: sd 3:0:0:0: [sdb] Attached SCSI removable disk
But sdb does not show up under lsblk and lsblk -a gives:

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NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
...
sda           8:0    1  3.8G  0 disk
sdb           8:16   1        0 disk
...
Note that sda (another USB stick) has an entry in the size column, but sdb does not.

fdisk /dev/sdb gives:

Code: Select all

fdisk: cannot open /dev/sdb: No medium found
Furthermore the USB cannot be recognized by OSX when inserted into my Mac.

Why does this happen? Is there any way to restore the USB stick (preferably without data loss).

clutch
Posts: 2
Joined: Sat Nov 23, 2013 1:54 pm

Re: My Pi destroys USB sticks

Sat Nov 23, 2013 1:57 pm

My Raspberry Pi just destroyed the third USB Key.

USB key is not recognized anymore, i've tried in several systems. It just won't light up.

I don't get it. I've tried with different power supply, most recent one was tested with multimeter and it produces 1.5A.

anders
Posts: 6
Joined: Fri Aug 16, 2013 2:09 am

Re: My Pi destroys USB sticks

Sat Nov 23, 2013 2:27 pm

I had a swap file on the USB stick. Disabling it solved my problems.

obcd
Posts: 917
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Re: My Pi destroys USB sticks

Sat Nov 23, 2013 2:32 pm

The power to the usb pors passes trough the Polyfuse.
Usb memory sticks can be very power hungry and probably your setup trips the polyfuse.

So, are the usb memory sticks connected directly to your PI? You have 2 of them connected?

I sometimes bridge the polyfuse with another additional 1 Amp polyfuse. This still gives some fire hazard protection but leaves a little more current for usb devices. It also decreases the conducting resistance of the 2 polyfuses and keeps the TP1 TP2 testvoltage closer to the expected 5V.

For windows, you can find a program called winhex that can analyse an usb disk on a sector based level. Another indication of the usb stick still showing a sign of life is if you get the icon to remove it. If windows can't locate valid partitions on the usb memory stick, it won't assign a drive letter. This can happen if the MBR or partition table becomes corrupted.

jamesh
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Re: My Pi destroys USB sticks

Sat Nov 23, 2013 5:08 pm

anders wrote:I had a swap file on the USB stick. Disabling it solved my problems.
Remember that USB drives are flash memory, same as SD cards, and pummelling them with swap or other high intensity read/writes will wear the flash out faster than normal usage.
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DougieLawson
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Re: My Pi destroys USB sticks

Sat Nov 23, 2013 8:51 pm

Remember that if you re-write the partition table on any removable device you need to physically eject it and re-insert it. Linux will re-read the partition table on insert and will then report the partitions it finds. That shows up in dmesg.
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clutch
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Joined: Sat Nov 23, 2013 1:54 pm

Re: My Pi destroys USB sticks

Sat Nov 23, 2013 9:41 pm

obcd wrote:The power to the usb pors passes trough the Polyfuse.
Usb memory sticks can be very power hungry and probably your setup trips the polyfuse.

So, are the usb memory sticks connected directly to your PI? You have 2 of them connected?

I sometimes bridge the polyfuse with another additional 1 Amp polyfuse. This still gives some fire hazard protection but leaves a little more current for usb devices. It also decreases the conducting resistance of the 2 polyfuses and keeps the TP1 TP2 testvoltage closer to the expected 5V.

For windows, you can find a program called winhex that can analyse an usb disk on a sector based level. Another indication of the usb stick still showing a sign of life is if you get the icon to remove it. If windows can't locate valid partitions on the usb memory stick, it won't assign a drive letter. This can happen if the MBR or partition table becomes corrupted.
Tnx for the info.

Yes, I have external HDD (with own power supply), USB stick and WIFI dongle.

I've just ordered a powered USB HUB. Could there be any problems if I power RPi with its current 1.5A power source and plug in USB HUB that has its own power source?

My USB key won't even light up. It's permanently damaged. It happened before (with other USB key) and one time with nano WIFI dongle.

I expected corrupted USB key on low power supply, but I got damaged USB key beyond the repair.

Fabo.sk
Posts: 1
Joined: Sun Apr 27, 2014 12:01 pm

Re: My Pi destroys USB sticks

Sun Apr 27, 2014 12:07 pm

I have just had this happen to me, during a power outage. Did any of you figure out a way to salvage the data? I can have my stick repaired under warranty, but I don't really feel like having to set the whole XBMC again.

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