Strange DISK messages

[Matthew Daubenspeck <matt (at) oddprocess.org>]

I've been getting a lot of these lately from several linux clients. It
just randomly appears, then goes away:

red Wed Mar  3 10:04:11 EST 2010 - Filesystems NOT ok                                                                   
&red 22% /mnt/foo (282464108% used) has reached the PANIC level (98%)                                                   
                                                                                                                        
Filesystem         1024-blocks      Used Available Capacity Mounted on                                                  
/dev/sdc1            307663800   8986508 283048860       4% /                                                           
/dev/sdb1            288435168 120484520 153298968      45% /mnt/300gb                                                  
/dev/sd                                                                                                                 
3    ]       377855068  75887248 282464108      22% /mnt/foo    

Any ideas where I should start poking around? I am using the latest Xymon beta client...
-- 
  Matthew Daubenspeck
  http://oddprocess.org

Gentoo Linux i686 Intel(R) Xeon(R) CPU L5420 @ 2.50GHz
13:15:31 up 125 days, 2:43, 5 users, load average: 0.03, 0.08, 0.03