So why do you need to downgrade? Is it due to some technical issue, or is
it a case where you are running with an incompatible server? If there is a
technical issue you should contact IBM support before giving up on 6.1 or
6.2.

At any rate: No, you cannot simply uninstall the 6.x client and reinstall
the 5.5 client and expect it to work okay. This will most likely cause
problems not only with restore, but with backup as well (active metadata is
at 6.1 level, which 5.5 client does not understand). If you are in a
position where there is no choice but to downgrade, then I suggest you
rename the existing node to something else, then create a new node with the
same name as the original node. Thus the next backup will be a complete
backup of everything. But if you need to access the older data, you can
still get to it (the data backed up with 6.x client will need the
corresponding 6.x client to restore). You can then delete the old node's
file spaces after the new backup file spaces are established. Before
deleting old data, be sure to take your policy set retention settings into
consideration (verexists, verdeleted, retextra, retonly) so you do not
delete data prematurely.

If this is especially critical data, proceed with caution and contact IBM
support for further guidance.

Best regards,

Andy

Andy Raibeck
IBM Software Group
Tivoli Storage Manager Client Product Development
Level 3 Team Lead
Internal Notes e-mail: Andrew Raibeck/Hartford/IBM@IBMUS
Internet e-mail: storman AT us.ibm DOT com

IBM Tivoli Storage Manager support web page:
http://www.ibm.com/support/entry/portal/Overview/Software/Tivoli/Tivoli_Storage_Manager


The only dumb question is the one that goes unasked.
The command line is your friend.
"Good enough" is the enemy of excellence.

"ADSM: Dist Stor Manager" <ADSM-L AT vm.marist DOT edu> wrote on 2010-09-02
04:24:43:

> From: Stefan Folkerts <stefan.folkerts AT ITAA DOT NL>
> To: ADSM-L AT vm.marist DOT edu
> Date: 2010-09-02 04:24
> Subject: Downgrading TSM 6.1/6.2 Windows clients to 5.5
> Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT vm.marist DOT edu>
>
> What are the consequences of downgrading a TSM client from 6.1/6.2
> to 5.5 on Windows?
> I expect the systemstate as it was backed-up using the 6.x clients
> won't restore but will file/archive restores work?
>
> Regards,
>   Stefan