Welcome to the most active Linux Forum on the web.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 03-31-2014, 04:23 PM   #1
LQ Newbie
Registered: Mar 2014
Posts: 2

Rep: Reputation: Disabled
Does starthead matter for mounting a USB drive?

My external USB key with 1 FAT partition has suddenly failed. The USB key was data-only - not used for booting.

When I mount:

root ~ # mount /dev/sdd1 /mnt
mount: you must specify the filesystem type
root ~ # mount /dev/sdd1 /mnt -t vfat
mount: wrong fs type, bad option, bad superblock on /dev/sdd1,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so
Looking at just the first few bytes and comparing it to another USB key, I wonder if the "starthead" has been changed or is incorrect:

Can't mount USB key #1:

mint ~ # dd if=/dev/sdd of=/tmp/5.img count=1000
1000+0 records in
1000+0 records out
512000 bytes (512 kB) copied, 0.035325 s, 14.5 MB/s
root ~ # file /tmp/5.img 
/tmp/5.img: x86 boot sector, Microsoft Windows XP MBR, Serial 0x23456789; partition 1: ID=0xc, active, starthead 1, startsector 34976, 62617440 sectors, code offset 0xc0
Can mount USB key #2:

root ~ # dd if=/dev/sde of=/tmp/5b.img count=1000
1000+0 records in
1000+0 records out
512000 bytes (512 kB) copied, 0.0211162 s, 24.2 MB/s
root ~ # file /tmp/5b.img
/tmp/5b.img: x86 boot sector, Microsoft Windows XP MBR, Serial 0x12345678; partition 1: ID=0xc, starthead 165, startsector 10456, 15660840 sectors, code offset 0xc0
On the can't-mount-USB the starthead is 1 whereas on the can-mount-USB the starthead 165. Could this be causing my problem in mounting a USB key that until now has work
Old 03-31-2014, 04:39 PM   #2
Registered: Dec 2010
Posts: 281

Rep: Reputation: 24
write cycles? mkfs?

maybe the flash just failed? have you hit more than 100K cycles?

also have you tried mkfs to ensure that you are correct in assuming the filesystem is fat

Last edited by cin_; 03-31-2014 at 04:43 PM. Reason: gramm`err
Old 03-31-2014, 06:02 PM   #3
LQ Newbie
Registered: Mar 2014
Posts: 2

Original Poster
Rep: Reputation: Disabled
yes the flash has gone flaky. It's about 1 year old, thought it would have lasted longer.

However, I can see data using hexdump - except it's raw data. I'm looking how I can salvage the data and believe that the partition table is slightly corrupted.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
fedora 7: autofs is not mounting USB flash drive or DVD ROM drive Hewson Linux - General 3 05-12-2008 08:58 AM
Mounting USB external drive with multiple partitions, USB bluetooth mouse xmeson Slackware 7 12-17-2006 09:00 AM
Mounting split raid drive as normal drive via USB William_Syd Linux - Newbie 2 11-01-2006 07:07 PM
USB drive mounting RohanShrivastav SUSE / openSUSE 10 06-08-2005 02:57 AM
Mounting my USB external drive, USB 1.1 Devillion Linux - Hardware 4 01-04-2004 09:11 AM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 07:50 AM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration