"cannot create directory" error

Hi there,

I got an old linux box running Redhat 9 I believe.  Now I cannot
create a new directory on a drive (under both root and regular
account) which is under /mnt/space.

Please see below for more info.  What can I have to fix the problem?

Any oopinion is appreciated.



 [user_name@linux1 user_name]$ pwd
/mnt/space/user_name

[user_name@linux1 user_name]$ su
Password:
[root@linux1 user_name]# mkdir ttt
mkdir: cannot create directory `ttt': Input/output error
[root@linux1 reggie]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda2             34265764  30536492   1988632   94% /
/dev/hda1                31079     17295     12180             59% /boot
none                   2063332         0   2063332                  0% /dev/shm
/dev/hdb1             38480404  33180376   3345324  91% /mnt/space
[root@linux1 user_name]#
[root@linux1 user_name]# uname -a
Linux linux1.zonatech.com 2.4.20-8bigmem #1 SMP Thu Mar 13 17:32:29 EST 2003 i68
6 i686 i386 GNU/Linux
[root@linux1 reggie]# date
Mon Sep 19 16:52:55 MDT 2011
[root@linux1 user_name]# exit
exit
[user_name@linux1 user_name]$ mkdir yyy
mkdir: cannot create directory `yyy': Input/output error