[Discuss] mount problem

[me at mattgillen.net (Matthew Gillen)]

On 8/28/2020 10:26 AM, dan moylan wrote:
> 
> On Thu, August 27, 2020 11:11 am, dan moylan wrote:
>>> i have two computers running:
>>>   arcturas, an intel nuc10, running fc31, and
>>>   aldeberon, an asus aspire E1-472P, also running fc31.
>>>
>>> my memory sticks always mount on /run/media/moylan for
>>> both computers.
>>>
>>> suddenly, for aldeberon, the memory stick refuses to mount:
>                 ...........
> 
> derek atkins writes:
>> Check dmesg output?
>> Check /var/log/messages?
>> Check the output of "mount"?
> 
> i did indeed check dmesg and mount output but found nothing
> of applicability.  it was only later that i discovered that
> /var/log/messages had been superseded by journalctl in
> fc31.
> 
> however, i rebooted and voila, the memory stick mounted.
> all is now well, but of course i understand nothing.

Might be that the automounter died.  dmesg should still have info about
the raw USB device and let you see what device file assignment it got
(e.g. [sdc], which you could then manually mount or dump its partition
table:
 fdisk -l /dev/sdc
)

Most USB sticks have a partition table and one or two partitions, so you
usually don't mount the raw device, but /dev/sdc1 (unless you've done
your own thing with it).

The dmesg should look something like this when you plug it in (fedora
31), regardless of whether the automount works (in my case, I could
manually mount /dev/sdi1 based on this output):

[1606372.382125] usb 2-1: new high-speed USB device number 3 using ehci-pci
[1606372.516600] usb 2-1: New USB device found, idVendor=XXX,
idProduct=XXXX, bcdDevice= 1.00
[1606372.516606] usb 2-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[1606372.516609] usb 2-1: Product: <Product Name>
[1606372.516612] usb 2-1: Manufacturer: <Your Mfg>
[1606372.516615] usb 2-1: SerialNumber: XXXXXX
[1606372.520039] usb-storage 2-1:1.0: USB Mass Storage device detected
[1606372.520298] scsi host9: usb-storage 2-1:1.0
[1606373.575557] scsi 9:0:0:0: Direct-Access     <Product> 2.0 PMAP PQ:
0 ANSI: 4
[1606373.576289] sd 9:0:0:0: Attached scsi generic sg8 type 0
[1606375.220206] sd 9:0:0:0: [sdi] 30497664 512-byte logical blocks:
(15.6 GB/14.5 GiB)
[1606375.220810] sd 9:0:0:0: [sdi] Write Protect is off
[1606375.220813] sd 9:0:0:0: [sdi] Mode Sense: 23 00 00 00
[1606375.221466] sd 9:0:0:0: [sdi] No Caching mode page found
[1606375.221471] sd 9:0:0:0: [sdi] Assuming drive cache: write through
[1606375.259017]  sdi: sdi1
[1606375.263316] sd 9:0:0:0: [sdi] Attached SCSI removable disk

HTH,
Matt