Thanks Joe,
I ran reiserfsck --check /dev/md2 and here is the reply:
root@Tower:/# reiserfsck --check /dev/md2
reiserfsck 3.6.19 (2003 www.namesys.com)
*************************************************************
** If you are using the latest reiserfsprogs and it fails **
** please email bug reports to
[email protected], **
** providing as much information as possible -- your **
** hardware, kernel, patches, settings, all reiserfsck **
** messages (including version), the reiserfsck logfile, **
** check the syslog file for any related information. **
** If you would like advice on using this program, support **
** is available for $25 at www.namesys.com/support.html. **
*************************************************************
Will read-only check consistency of the filesystem on /dev/md2
Will put log info to 'stdout'
Do you want to run this program?[N/Yes] (note need to type Yes if you do):Yes
###########
reiserfsck --check started at Wed Jun 16 18:39:39 2010
###########
Replaying journal..
Reiserfs journal '/dev/md2' in blocks [18..8211]: 0 transactions replayed
Checking internal tree..
Bad root block 0. (--rebuild-tree did not complete)
Aborted
I will proceed according to your advise (reiserfsck --rebuild-tree -S /dev/md2)
I have 1GB RAM but I guess the issue was that my Mac was going to sleep.