Migrating to hashed directories

[Steve Perrault]

Running Qpopper 4.0.4 on a Sun e450.  Running in 
servermode/standalone.  I'm also using sendmail+procmail for 
sending/delivery.  We average between 150/170 POP3 sessions/min.

To tweak directory access, I'd like to migrate my user's mail files to the 
2nd style of directory hashing

ie, ( /var/mail/biff => /var/mail/b/i/biff )

I know the safest way would be to take down mail while I merely copy files, 
but  I'd prefer to avoid any interruption.

I see qpopper has a safety feature where it will look for the unhashed file 
by default when hashing is activated.  Does this mean it will merge email 
from 4 different files into one file when the users checks email?  (the 4 
files being both hashed and unhashed mail files and hashed/unhashed .pop files)

- SteveP