Read Only File System

[Ian Chapman]

tony.chamberlain at lemko.com wrote:

> I heard sometimes if linux encounters errors in a disk it will remount 
> it as read only.

Yes that's correct. I believe it's a tuneable option for ext3 
filesystems (man tune2fs)

> A mount -l however shows it as
> 
> /dev/sdb1 on /home2 type ext3 (rw) []
> 
> and ls -ls on it:  4 drwxrwxr-x  9 root cusload 4096 Oct  3 10:19 /home2
> So it appears to be writable.

Unfortunately mount can be misleading in this respect. It shows the 
options used to mount the filesystem at mount time, not it's current state.

> Doing antyhing like > /home2/test or vi /home2/test (or any subdirectory)
> 
> gives errors though about not being able to write (or read only file 
> system).
> 
> Any idea what is going on? 

You almost certainly have disk errors on this partition, type dmesg or 
have a look in /var/log/messages where you'll probably see lots of disk 
error output. Take the partition offline if possible and run fsck on it.

-- 
Ian Chapman.