Need a USB Flash Drive Wizard

Getting your soundcard to work, using Debian on non-i386 hardware, etc

Re: Need a USB Flash Drive Wizard

Postby Segfault » 2018-04-04 12:33

It is flashing because it is writing cached data. Wait until it finishes before pulling it.
Last edited by Segfault on 2018-04-04 12:38, edited 1 time in total.
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Re: Need a USB Flash Drive Wizard

Postby dcihon » 2018-04-04 12:38

So I don't understand then.
If I put the flash drive into the computer and it mounts. I immediately eject without writing anything to it.
The drive is flashing rapidly and it stays that way. How long should I have to wait?
I don't seem to have to do that with other flash drives.
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Re: Need a USB Flash Drive Wizard

Postby bw123 » 2018-04-04 14:05

dcihon wrote:This is what it shows when I plug it in:
Code: Select all
root@cihonm:~ # dmesg | tail
[66757.664309] scsi host4: usb-storage 1-8.5:1.0
[66758.667401] scsi 4:0:0:0: Direct-Access     General  UDisk            5.00 PQ: 0 ANSI: 2
[66758.668087] sd 4:0:0:0: Attached scsi generic sg2 type 0
[66758.668330] sd 4:0:0:0: [sdb] 131072000 512-byte logical blocks: (67.1 GB/62.5 GiB)
[66758.668522] sd 4:0:0:0: [sdb] Write Protect is off
[66758.668527] sd 4:0:0:0: [sdb] Mode Sense: 0b 00 00 08
[66758.668729] sd 4:0:0:0: [sdb] No Caching mode page found
[66758.668738] sd 4:0:0:0: [sdb] Assuming drive cache: write through
[66758.670214]  sdb: sdb1
[66758.671307] sd 4:0:0:0: [sdb] Attached SCSI removable disk

The light on the USB drive is solid.
When I eject it the Device description changes from 67 GB Volume to General UDisk: 67 GB Volume and the light is flashing very rapidly. So it doesn't get fully ejected.
The only way I have found to fully eject it is after ejecting it from the file manager then open Disks and power it off. If I just take it out when it is flashing then it write protects it and I can't add or delete anything on it.
Should I buy a more expensive flash drive?
What I am going to use this flash drive for is listening to my mp3 files in my car.

I've never seen one act like that, and the "assuming write through" stuff kind of reminds me of using a floppy?. Maybe you can get more info by looking at dmesg during the whole insert/mount/eject thing...

I have good luck with the cheap usb flash drives. I won't mention any brands but you know them I'm sure. The general way the led seems to work usually is:
Plug it in,
led starts to blink fairly steady about 7 times.
led then begins to fade in and out slowly (idle)
led blinks rapidly when mounted, then idle.
led blinks rapidly when reading/writing, then idle.
led blinks rapidly when umount, then idle.

Are you sure you haven't setup some doodad to sync or open the thing automatically? You really don't want to unplug it when something is accessing it. You can use something like fuser to find out if anything has it open.

I use dosfsck with the second verification pass to fix mine when it gets dirty bit:
$ man dosfsck
# dosfsck -avV

On occasion FAT32 can get so twisted up that only an old ver of chkdsk from dos or early windows can straighten it out. It's pretty reliable on linux though.
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Re: Need a USB Flash Drive Wizard

Postby dcihon » 2018-04-04 17:39

Yea I threw the first one away and bought a new one.
This whole thing with ejecting is on a new flash drive.
I will try some of the suggestions and post back.
Should I start a different thread?
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Re: Need a USB Flash Drive Wizard

Postby pylkko » 2018-04-04 20:03

we have seen this same problem on this forum, and also on other forums around the internet. unfortunately flash media (referring here to sd-cards and usb sticks specifically) are complex. they are essentially computers, they have processors, RAM and run a firmware which out of the reach of the average user (i say this because there are people who have managed to hack these firmwares and use sd-cards as microcontrollers). the firmware does things like wear leveling, which can apparently even occur when the OS is shut down.

from all of this it follows that it is not wise to invest much in flash media (unless it come with a mega warranty, and even then expect occasional data loss - i have had two sepreate usb sticks sent back to the manufacturer twice and replace with a new one that had to be sent back also). people who use them frequently (for example people running RPi's usually backup the entire image and then when bad stuff happens they reflash it to the same media or to a new one. they are temporary devices for moving data from point A to point B bur not for storage.

personally, have noticed that they are also very poorly tolerant to heat, and that this appears to be worse with the smaller form factor ones, like the really stub/miniscule usb sticks. on the RPi forums there are several reports of manufactures not accpeting to refund broken sd-cards under warranty because they were used in applications where they are in constant use. i suspect that this has to do with them not having cooling systems, and they therefore work if you only pop them in and move a few files for a few mins max. anything more than that causes heat and significant wear.
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Re: Need a USB Flash Drive Wizard

Postby dcihon » 2018-04-04 20:16

Code: Select all
root@cihonm:~ # dosfsck -avV /dev/sdb1                                                                                                                                       
fsck.fat 4.1 (2017-01-24)
Checking we can access the last sector of the filesystem
0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
 Automatically removing dirty bit.
Boot sector contents:
System ID "mkfs.fat"
Media byte 0xf8 (hard disk)
       512 bytes per logical sector
     32768 bytes per cluster
        64 reserved sectors
First FAT starts at byte 32768 (sector 64)
         2 FATs, 32 bit entries
   8192000 bytes per FAT (= 16000 sectors)
Root directory start at cluster 2 (arbitrary size)
Data area starts at byte 16416768 (sector 32064)
   2047467 data clusters (67091398656 bytes)
32 sectors/track, 64 heads
      2048 hidden sectors
 131069952 sectors total
Starting check/repair pass.
Reclaiming unconnected clusters.
Checking free cluster summary.
Starting verification pass.
Checking for unused clusters.
Performing changes.
/dev/sdb1: 1085 files, 116565/2047467 clusters
1|root@cihonm:~ # fsck /dev/sdb1                                                                                                                                             
fsck from util-linux 2.31.1
fsck.fat 4.1 (2017-01-24)
/dev/sdb1: 1085 files, 116565/2047467 clusters
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