Dmitri,

To answer your questions:

Q: Why is Gresham's EDT product required as part of the Storage
Agent/LAN-Free solution?
A: Gresham's EDT product was selected to handle tape resource brokering
between TSM and ACSLS/LibStation.  In particular, EDT-DistribuTAPE enables
TSM to use a single scratch pool between multiple TSM servers.
EDT-DistribuTAPE ensures that when multiple TSM servers use a single scratch
pool, tapes that are in use by one TSM server are not allocated to other TSM
servers ensuring that data integrity is maintained and data is protected on
each volume.

Q: What are the issues involved with sharing ACSLS between multiple TSM
servers?
A: If you do not use EDT-DistribuTAPE in a solution where you have multiple
TSM servers accessing a single ACSLS server, the largest problem that you
will face is the fact that TSM is designed to employ ACSLS scratch pool 0.
Since multiple TSM servers would be accessing the same tape pool, you cannot
ensure that a volume that is in use by one TSM server will not be assigned
and overwritten by another TSM server.

Q: What is EDT's exact role in LAN-Free data transfer?
A: EDT-DistribuTAPE is responsible for satisfying mount requests, ensuring
that the proper tape volume has been mounted, that the volume is properly
prepared for use and that the data path has been properly established.  Once
this process has been completed, EDT-DistribuTAPE turns control over to TSM
along with all appropriate information allowing TSM to perform the backup.
EDT-DistribuTAPE does not actively participate on the data path.

Q: Has anyone setup an ACSLS library for SAN using EDT?
A: Gresham has numerous clients who use EDT-DistribuTAPE with
ACSLS/LibStation and TSM in a SAN environment.  Lately, Gresham has deployed
LAN-Free solutions at several locations all with great success.

For additional information, please refer to www.gresham-software.com/tivoli.

Christopher S. Young
Senior System Engineer
Gresham Enterprise Storage
www.greshamstorage.com
Office: 303.413.1799 x 205
Mobile: 303.717.2745