Just adding to Greg's post,
The Single Instance Archiving or SIA is part of the LEA server.It was primarily designed to handle email situations where an email with the same attachment was send to several different people.SIA would store only one copy of the attachment.Also LEA is used in the context of long term cheap storage where very cheap archiving media such as optical,worm etc are used.With electromagnetic media now getting very cheap I have even seen LES servers using LEA as primary storage.LEA also provides Time Stamping service where one can time stamp the file on creation which make it almost impossible to manipulate the file in the file store(Some regulatory authorities require proof that EFS cannot be changed)
Well, if I called the wrong number, why did you answer the phone?
James Thurber, New Yorker cartoon caption, June 5, 1937
Certified OT Developer and probably certfiable,Livelink ECM Champion 2008