What is filesystem panic?

[Per Anton Rønning]

James Wilkinson wrote:
> Per Anton Rønning wrote:
>   
>> I guess I should rephrase my question about my 4GB memory stick/pen,  
>> where the filesystem
>> now is set to readonly when I enter it into one of the slots.
>> Could anyone tell me what might have happened by taking a look at the  
>> snip of the logfile?
>>
>> I am not allowed to do anyting but reading files. I am not allowed to  
>> delete files ,remove directires
>> or write to files, even if I change to root privileges.
>> I cannot say when this started - it just happened one time when I tried  
>> to backup some files to the Jet Flash.
>> Then I got the message (one example):
>>  cp: cannot create regular file `/media/disk/trade/statQ': Read-only  
>> file system
>> Does anyone have a clue? I'd be grateful for pointers in the right  
>> direction.
>>     
> <snip>
>   
>> Oct 27 11:36:30 localhost kernel:    fat_free_clusters: deleting FAT  
>> entry beyond EOF  [My remark: What does this
>>                                                                           
>>                                                  mean? Looks like an  
>> error message]
>> Oct 27 11:36:30 localhost kernel:    File system has been set read-only  
>> [!!!!!!! - my remark]
>> *** end snip ***
>>     
>
> It looks to me like this is a logical inconsistency with the filesystem
> on the drive.  Did you create it, or is it as the drive came?
>
> A number of these drives come with slightly inconsistent partitioning
> and formatting – it looks like this is becoming a FAQ. It’s possible
> (but rather unlikely) that a stray Linux bug or memory errors corrupted
> something. It’s slightly more likely that a bug in the drive itself
> corrupted something.
>
> In any of these cases, I’d recommend backing up everything that’s on the
> disk, and either:
>  * fdisk it to remove and recreate any partitions, then mkfs a new
>    filesystem
>  * just mkfs a filesystem on the “raw” device (e.g. /dev/sdc rather than
>    /dev/sdc1).
>
> Hints: the fdisk man page recommends cfdisk or parted to the traditional
> fdisk program: you might want to try the graphical gparted. If you want
> to use this disk under Windows, use
> mkfs -t fat32 -F 32 -n diskname /dev/sdx
> where diskname is the name you want to give the disk.
>
> And make sure you do this on the right device! There is always the
> prospect with these devices, if you’re not careful, of screwing up your
> hard disk!
>
> It’s vaguely possible that this disk’s reached its maximum number of
> rewrites and has no spare sectors to swap in. If this is the case, then
> it’s basically dead – it just allows you to get all the data off it.
> (This seems to be the most normal failure mode with Flash, and is
> definitely a Good Thing).
>
> In any case, and as a general principle, never trust any disk too much.
> If you haven’t got multiple copies of a piece of data (in multiple
> locations), you haven’t really got it.
>
> Hope this helps,
>
> James.
>
>   
Thanks James.
I did not create it, the flash pen was ready to go when I got it. I just
created the necessary directories on it and started copying to it.
I also used it to tranfer data and programs from an old computer
(running FC5), which was very convenient.

But now the pen seems to be really stuck, just look at this:

[root at localhost disk]# /sbin/fdisk /dev/sdc
Unable to open /dev/sdc

And also:
[root at localhost disk]# /sbin/fdisk /dev/sdc1
Unable to open /dev/sdc1

This is not a disaster, it just means that I have to consider this flash 
pen obsolete and buy a new one.
I have been using it for backup of some hard disk directories,  so it is 
no big deal if I lose whats on it, since my harrdisk is intact.

Perhaps I should buy a  removable HD instead.

BRGDS
PAR