USB read only issues

[dunnigan14]

Hello everyone I am hoping maybe someone could shed some light on a problem I have been having recently. I am working on a masters thesis, which I keep on my Sony usb thumb drive(with periodic backups to hard disk).

My problem is that randomly the drive will go from read/write to read only. This kinda sucks as your writing some code and all the sudden you cannot save. but mount seems to shows "dev/sdc1 on /media/disk" still being read/write, :

~]# mount
/dev/sda2 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sdb2 on /home type ext3 (rw)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/dev/sdc1 on /media/disk type vfat (rw,nosuid,nodev,uhelper=hal,shortname=lower,uid=501)
/dev/sdd2 on /media/IPOD type vfat (rw,nosuid,nodev,uhelper=hal,shortname=lower,uid=501)

I can see in /var/log/messages that there is a FAT panic:

Sep 20 14:59:16 localhost kernel: FAT: Filesystem panic (dev sdc1)
Sep 20 14:59:16 localhost kernel:     fat_free_clusters: deleting FAT entry beyond EOF
Sep 20 14:59:16 localhost kernel:     File system has been set read-only

So really my question comes down to, why the heck is this happening? If anyone can shed some light on this for me it would be great, any more info you need let me know.

Thanks everyone!!

[my_linux]

I have the same problem with a Seagate FreeAgent Go drive formated Ext3 which powers off of USB. Yet another drive which powers off of the mains works just fine.

Any ideas anyone?

[olenb]

I think the hard drives are malfunctioning/dying

[my_linux]

I don't agree as if the drive is formated NTFS and used with Windows there are no problems.

I have also found the following which may help: http://www.debianhelp.org/node/7619 and http://ubuntuforums.org/archive/index.php/t-329856.html