[SOLVED] external drive mounts as 'read-only'? Lucid Lynx

Nizzok · 05-19-2010, 05:59 AM

Hi All,

I just upgraded to lucid lynx, and my trusty external harddrive is now somehow mounting as 'read-only'. What's happened, and how do I fix this? I've gone to the mount point /media/My Passport, the permissions are dwrx-----24, and read-write for my user. When I view the permissions through the desktop file explorer, it says the permissions can't be determined. The drive's fat32. Running on a lenovo g450

ewaller · 05-19-2010, 06:43 PM

How are you mounting the drive?

Using Hal/Dbus?
Have you an entry in /etc/fstab allowing users to mount it?
are you using the mount command with root privileges?

Lets start with the output of:

mount

and

cat /etc/fstab

Thanks.

Nizzok · 05-20-2010, 12:26 AM

Hi,

I was just mounting the drive via the auto-mount. I had no problems in karmic, and a few days after switching to lynx, the drive starts to mount as read-only. I've tried mount -f and umount -f, but that doesn't seem to affect the read status. I've also unsuccessfully tried chmoding (noob).

Here's the result of mount (I should mention I'm running badblocks while the usb drive on /dev/sdb1 is unmounted):

Code:

/dev/sda5 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw)
none on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
none on /dev type devtmpfs (rw,mode=0755)
none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
none on /dev/shm type tmpfs (rw,nosuid,nodev)
none on /var/run type tmpfs (rw,nosuid,mode=0755)
none on /var/lock type tmpfs (rw,noexec,nosuid,nodev)
none on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
gvfs-fuse-daemon on /home/nicholas/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=nicholas)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nod

Here's the result of the cat /etc/fstab

Code:

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# / was on /dev/sda5 during installation
UUID=6095d8c8-7683-47e9-ad9c-8e47c8b8486c /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda6 during installation
UUID=9377517a-0835-49a3-8939-1f35f2c2d58e none            swap    sw              0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0       0

I've also included the dosfsck I ran. I've bolded where I think something is going wrong, but I'm not sure where/how to proceed.

Code:

dosfsck -a -v /dev/sdb1
dosfsck 3.0.7 (24 Dec 2009)
dosfsck 3.0.7, 24 Dec 2009, FAT32, LFN
Checking we can access the last sector of the filesystem
There are differences between boot sector and its backup.
Differences: (offset:original/backup)
  67:28/54, 68:fd/1f, 69:0f/fb, 70:d9/16, 72:59/79, 73:5f/20, 74:45/50
  , 75:58/61, 76:54/73, 77:45/73, 78:52/70, 79:4e/6f, 80:41/72, 81:4c/74
  Not automatically fixing this.
Boot sector contents:
System ID "MSWIN4.1"
Media byte 0xf8 (hard disk)
       512 bytes per logical sector
     32768 bytes per cluster
        32 reserved sectors
First FAT starts at byte 16384 (sector 32)
         2 FATs, 32 bit entries
  61040640 bytes per FAT (= 119220 sectors)
Root directory start at cluster 2 (arbitrary size)
Data area starts at byte 122097664 (sector 238472)
  15258273 data clusters (499983089664 bytes)
63 sectors/track, 255 heads
        63 hidden sectors
 976768002 sectors total
/saa2010
  Contains a free cluster (4716032). Assuming EOF.
Reclaiming unconnected clusters.
Unable to create unique name

Also, the result of trying to mess within the drive as sudo...
[code]
nicholas@theseus:/media/MY_EXTERNAL/Nick_files$ cp usgs.pdf usgs2.pdf
cp: cannot create regular file `usgs2.pdf': Read-only file system
nicholas@theseus:/media/MY_EXTERNAL/Nick_files$ sudo cp usgs.pdf usgs2.pdf
[sudo] password for nicholas:
cp: cannot create regular file `usgs2.pdf': Read-only file system
nicholas@theseus:/media/MY_EXTERNAL/Nick_files$ sudo su
root@theseus:/media/MY_EXTERNAL/Nick_files# cp usgs.pdf usgs2.pdf
cp: cannot create regular file `usgs2.pdf': Read-only file system
root@theseus:/media/MY_EXTERNAL/Nick_files#
[code/]

Nizzok · 05-20-2010, 02:48 AM

I just noticed, my ipod doesn't work! well, dmesg recognizes it but it doesn't get loaded or recognized by rhythmbox...

tommyttt · 05-21-2010, 03:23 AM

Quote:

Originally Posted by Nizzok

I just noticed, my ipod doesn't work! well, dmesg recognizes it but it doesn't get loaded or recognized by rhythmbox...

From your previous post -- NEVER EVER run dos/windows checks on a linux partition! Use a live boot CD/DVD and run fsck.ext3 (or correct extension type).

Please do not add comments within the [CODE] blocks, just makes it harder to follow the logic. That said, the fstab looks a little odd, the 1st line with the UUID appears to be missing some options although that could be Ubuntus' style.

Here is one from my openSUSE 11.3:

Code:

/dev/disk/by-id/ata-ST9500420AS_5VJ1AKS0-part11 /    ext3    acl,user_xattr   1 1

For some reason your system thinks there is an error on that partition and so is mounting it RO.

Bratmon · 05-21-2010, 04:39 PM

Here's my Ubuntu /etc/fstab , for what it's worth:

Code:

# /etc/fstab: static file system information.
#
# Use 'vol_id --uuid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# / was on /dev/sda5 during installation
UUID=16d3e6f0-263b-4874-b3cc-fbc4b0f42dd4 /               ext3    relatime,errors=remount-ro 0       1
# swap was on /dev/sda6 during installation
# swap was by UUID, but was manually changed to traditional
/dev/sda6       none            swap    sw              0       0
/dev/scd1       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0

Nizzok · 05-22-2010, 12:18 AM

Hello all,

first, above: thanks for the advice. It was a FAT32 formatted external harddive, so the dosfsck was perfectly legitimate to run, as would chkdsk, to fix the drive if attached to a windoze box(at least what my reading has suggested). fsck was what tipped me off to the true nature of the problem anyway.

Next, sorry, I'm not terribly familiar with the forum's formatting, I didn't expect it to just put the code tags in.

Finally, the issue at heart seems to be that there were bad-sectors on the external. I've backed it up, formatted, and it works like a charm! Now if the ipod would work...

catkin · 05-22-2010, 12:33 AM

Glad you found the solution

and hope that you don't get more bad sectors. It's strange that there were any becuase modern hard drives detect bad sectors for themselves and stop using them (they have a pool of spare sectors to use instead).

The Thread Tools menu can be used to mark the thread SOLVED.

catkin · 05-22-2010, 12:34 AM

Duplicate post text removed