mount error for external usb ext3 drive: device not found
Linux - GeneralThis Linux forum is for general Linux questions and discussion.
If it is Linux Related and doesn't seem to fit in any other forum then this is the place.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
mount error for external usb ext3 drive: device not found
Hi,
I am having trouble to mount this external drive both as sudo and as root. This drive is formatted to ext3, and the system is CentOS 5. I remember mounitng similar drives in similar fasion in this machine. But I do not understand what is going wrong this time. Here are my results of fdisk and mount command:
Code:
somesh@archean media$ sudo /sbin/fdisk -l
Disk /dev/sda: 300.0 GB, 300000000000 bytes
255 heads, 63 sectors/track, 36472 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 25 200781 83 Linux
/dev/sda2 26 2065 16386300 82 Linux swap / Solaris
/dev/sda3 2066 3977 15358140 83 Linux
/dev/sda4 3978 36472 261016087+ 5 Extended
/dev/sda5 3978 4614 5116671 83 Linux
/dev/sda6 4615 36472 255899353+ 83 Linux
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 121601 976760001 83 Linux
somesh@archean media$ sudo mount -t ext3 /dev/sdc1 USB_Bkup/
mount: special device /dev/sdc1 does not exist
The sudoers file is:
Code:
## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
...
## Mount
Cmnd_Alias MOUNT = /sbin/fdisk, /sbin/sfdisk, /bin/mount, /bin/umount
...
%group.sudo-all ALL=(ALL) ALL
%access.workstations ALL=NOPASSWD:MOUNT
I am member of both group.sudo-all and access.workstations groups.
And this is the fstab file:
You might have to do this as well... to find the volume group on the disk.
Code:
vgscan
Still nothing. Actually vgdisplay and vgscan shows nothing!
Code:
-bash-3.2# vgdisplay -v
Finding all volume groups
-bash-3.2# vgscan
Reading all physical volumes. This may take a while...
-bash-3.2# vgdisplay -v
Finding all volume groups
-bash-3.2# fdisk -l
Disk /dev/sda: 300.0 GB, 300000000000 bytes
255 heads, 63 sectors/track, 36472 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 25 200781 83 Linux
/dev/sda2 26 2065 16386300 82 Linux swap / Solaris
/dev/sda3 2066 3977 15358140 83 Linux
/dev/sda4 3978 36472 261016087+ 5 Extended
/dev/sda5 3978 4614 5116671 83 Linux
/dev/sda6 4615 36472 255899353+ 83 Linux
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 121601 976760001 83 Linux
-bash-3.2# mount -t ext3 /dev/sdc1 /media/USB_Bkup
mount: special device /dev/sdc1 does not exist
ls -alh /dev/sdc*
file /dev/sdc1
dmesg | grep sdc
lsusb
There is no entry for /dev/sdc1
Code:
-bash-3.2# ls -alh /dev/sdc*
brw-r----- 1 root disk 8, 32 Mar 15 12:43 /dev/sdc
-bash-3.2# file /dev/sdc1
/dev/sdc1: ERROR: cannot open `/dev/sdc1' (No such file or directory)
This lead me to do this:
Code:
-bash-3.2# ls -alhrt /dev/* | tail -n 30
crw------- 1 root root 13, 67 Feb 21 09:39 event3
drwxr-xr-x 2 root root 200 Feb 21 09:39 .
drwxr-xr-x 13 root root 4.5K Mar 15 12:43 ..
/dev/cpu:
total 0
drwxr-xr-x 2 root root 80 Feb 21 09:39 6
drwxr-xr-x 2 root root 80 Feb 21 09:39 7
drwxr-xr-x 2 root root 80 Feb 21 09:39 4
drwxr-xr-x 2 root root 80 Feb 21 09:39 3
drwxr-xr-x 2 root root 80 Feb 21 09:39 5
drwxr-xr-x 2 root root 80 Feb 21 09:39 2
drwxr-xr-x 2 root root 80 Feb 21 09:39 1
drwxr-xr-x 2 root root 80 Feb 21 09:39 0
drwxr-xr-x 10 root root 200 Feb 21 09:39 .
drwxr-xr-x 13 root root 4.5K Mar 15 12:43 ..
/dev/shm:
total 12K
-rw-rw-rw- 1 somesh somesh 16 Feb 22 12:00 sem.ADBE_WritePrefs_somesh
-rw-rw-rw- 1 somesh somesh 16 Feb 22 12:00 sem.ADBE_REL_somesh
-rw-rw-rw- 1 somesh somesh 16 Feb 22 12:00 sem.ADBE_ReadPrefs_somesh
drwxrwxrwt 2 root root 100 Feb 22 12:00 .
drwxr-xr-x 13 root root 4.5K Mar 15 12:43 ..
/dev/usbdevices:
total 0
lrwxrwxrwx 1 root root 7 Mar 15 12:43 samsung1tb -> ../Bkup
drwxr-xr-x 13 root root 4.5K Mar 15 12:43 ..
drwxr-xr-x 2 root root 60 Mar 15 12:43 .
Looking at the dates, I then issued this mount command:
Code:
mount -t ext3 /dev/usbdevices/samsung1tb /media/USB_Bkup
and voila! It worked.
But that brings the question that why fdisk is showing something when that is not correct. Also why does this usb device going to /dev/usbdevices/samsung1tb ?
FYI, I tried various automount options with this drive in this machine long ago using udev and label. And some of them worked, before I switched to sudo based mounting! Now I have commented out all such commands in fstab. Also I formatted this drive from NTFS to EXT3 just an hour ago!
So why is fdisk is pointing at something else?
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.