I've got Slackware 10.1 and have had mild success using flash drives. Currently, the kernel thinks that my flash drive is busy or has a problem. Here's some output attempting to solve the problem:

1) Looking for my drive...
(using tail /var/log/messages)
Sep 5 23:55:56 TELDAR kernel: hub.c: new USB device 00:10.4-6, assigned address 9
---
(using dmesg | tail)
hub.c: new USB device 00:10.4-6, assigned address 9
WARNING: USB Mass Storage data integrity not assured
USB Mass Storage device found at 9
---

2) Errors from mounting the drive...
# mount /mnt/usbstick
mount: /dev/sda1 is not a valid block device
---
# mount -t vfat /dev/sda /mnt/usbstick
mount: wrong fs type, bad option, bad superblock on /dev/sda,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
---
Note: Attempting to specify any sda* device other then /dev/sda gets me "mount: /dev/sda3 is not a valid block device" as an error.
---
# tail /var/log/messages
Sep 5 23:55:56 TELDAR kernel: hub.c: new USB device 00:10.4-6, assigned address 9
Sep 5 23:57:31 TELDAR kernel: sda: Unit Not Ready, sense:
Sep 5 23:57:31 TELDAR kernel: sda: I/O error: dev 08:00, sector 0
Sep 5 23:57:46 TELDAR kernel: sda: Unit Not Ready, sense:
Sep 5 23:57:46 TELDAR kernel: sda: I/O error: dev 08:00, sector 0
Sep 5 23:57:46 TELDAR kernel: Device 08:00 not ready.
Sep 5 23:57:46 TELDAR kernel: sda: Unit Not Ready, sense:
Sep 5 23:57:46 TELDAR kernel: sda: I/O error: dev 08:00, sector 0
---
# dmesg | tail
Raw sense data:0x70 0x00 0x02 0x00 0x00 0x0a 0x00 0x00
sda : READ CAPACITY failed.
sda : status = 1, message = 00, host = 0, driver = 08
Info fld=0xa00 (nonstd), Current sd00:00: sns = 70 2
Raw sense data:0x70 0x00 0x02 0x00 0x00 0x0a 0x00 0x00
sda : block size assumed to be 512 bytes, disk size 1GB.
sda: test WP failed, assume Write Enabled
sda: I/O error: dev 08:00, sector 0
I/O error: dev 08:00, sector 0
unable to read partition table
---
3) Here's my /etc/fstab:
/dev/hda1 swap swap defaults 0 0
/dev/hda3 / ext3 defaults 1 1
/dev/hda2 /home ext3 defaults 1 2
/dev/cdrom /mnt/cdrom iso9660 noauto,owner,ro 0 0
/dev/fd0 /mnt/floppy auto noauto,owner 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
proc /proc proc defaults 0 0
/dev/sda1 /mnt/usbstick vfat user,noauto,umask=0 0 0
---

Help! I'm exasperated. I can get it to work on other machines just fine...

Which kernel are you using?
Have you made any changes to the default 2.4.29 kernel?

What is the manufacturer / model of the flash drive?
Are you sure of the filesystem?

Please take the following steps to remedy the problem:

First:
Remove the flash disk from your computer if it's not already.
Change your /etc/fstab entry to this:I am assuming you created the mount point /mnt/usbstick. This will allow
you to mount the device as a normal user, so don't try mounting as root.
The kernel will mount a partition, not a device, so /dev/sda1 is correct.

Second:
After changing your /etc/fstab, issue as root "/etc/rc.d/rc.hotplug restart"
and then exit from root to a normal user. Then issue "dmesg | grep -i usb"
and post that output.

Third:
Now plug the flash disk into your computer and wait 30 seconds and
then issue "dmesg | tail" and post the output. Then issue as a normal
user "mount /mnt/usbstick" and if it returns to a prompt with no other
output, it's mounted. You can then issue "cd /mnt/usbstick" and it will
read/write as a normal user. If it does return some other output, then
post that here; along with the output of "dmesg | tail" again after you
tried to mount the device.

Fourth:
With the device still plugged in, issue as root "/etc/rc.d/rc.hotplug restart"
once again and then as a normal user issue "mount /mnt/usbstick" and
if that doesn't mount it issue "dmesg | tail" again for the new messages.

I have a similar problem on mine trying to use a Lexar Jumpdrive Trio. Running Slackware 10.1 with kernel 2.6.11, when I plug mine in smetimes I get the "not a valid block device" error. If I do 'ls -l /dev/sda1' I'll see something like crwxrwxrwx indicating it was detected as a character device. I have to keep unplugging and plugging it in until it gets detected as a block device (brwxrwxrwx). My laptop, also Slack10.1 with 2.6.11, doesn't do this. I suspect kernel options

Yay! It all worked! Here's the output from dmesg | tail, just to be thorough:

scsi1 : SCSI emulation for USB Mass Storage devices
Vendor: Kingston Model: DataTraveler 2.0 Rev: 1.00
Type: Direct-Access ANSI SCSI revision: 02
Attached scsi removable disk sda at scsi1, channel 0, id 0, lun 0
SCSI device sda: 985088 512-byte hdwr sectors (504 MB)
sda: Write Protect is off
sda: sda1
WARNING: USB Mass Storage data integrity not assured
USB Mass Storage device found at 2
USB Mass Storage support registered.
---
After mounting & restarting hotplug:
hub.c: 2 ports detected
PCI: Found IRQ 11 for device 00:10.3
PCI: Sharing IRQ 11 with 00:10.2
uhci.c: USB UHCI at I/O 0xdc00, IRQ 11
usb.c: new USB bus registered, assigned bus number 5
hub.c: USB hub found
hub.c: 2 ports detected
hub.c: new USB device 00:10.4-6, assigned address 2
WARNING: USB Mass Storage data integrity not assured
USB Mass Storage device found at 2
---

Thank you!

You're welcome. If you ever have trouble with a USB device,
remember to restart hotplug as I showed you. Also, you want
to be certain that you have EHCI enabled in your kernel, which
is for USB 2.0 so that you get that 480 MB/s speed when you
have a USB 2.0 device. And dmesg can always show you where
the kernel sees the device. Sometimes it can be /dev/sdb1 or
other, if you have multiple devices mounted.

agpgart: Putting AGP V2 device at 0000:01:00.0 into 4x mode
agpgart: Found an AGP 2.0 compliant device at 0000:00:00.0.
agpgart: Putting AGP V2 device at 0000:00:00.0 into 4x mode
agpgart: Putting AGP V2 device at 0000:01:00.0 into 4x mode
usb 1-3: new full speed USB device using ohci_hcd and address 3
usb 1-3: USB disconnect, address 3
usb 1-3: new full speed USB device using ohci_hcd and address 5
usb 1-3: USB disconnect, address 5
usb 1-3: new full speed USB device using ohci_hcd and address 6

i just cant get my usb drive to work its driving me fjail crazy theres my dmesg | tail thingy

and im using kernel 2.6.13

from looking at that it looks like my pc is seeing that its plugged in i just cant get to it.
idk its driving me crazy

and also my sound isnt working anymore its not detecting a sound card now!! WTF its getting anoying

how do you mount a lexar jumpdrive in linux-mandrake 7.2?