Pete, et al,
My apologies for disseminating bad information, and thanks for the 
clarification.
..Paul

At 01:08 PM 2/14/2012, Pete Tanenhaus wrote:
>Actually this really isn't correct, a snapshot differential backup will
>detect deleted files and will expire them on the TSM server.
>
>Periodic full progressive incremental backups are recommended because "less
>complete" backups such as snapdiff,
>incremental by date, and JBB can never be as comprehensive as a full
>progressive given that a full progressive examines
>every file on the local file system and every file in the TSM server
>inventory.
>
>Note that "less complete" implies that changes processed by a full
>progressive might be missed by other "less complete"
>backup methods, and this is the reasoning behind recommending periodic full
>progressive incrementals.
>
>JBB is somewhat better in that in makes every attempt to detect conditions
>which indicate that the change journal is out of
>sync with what has previously been backed up and to automatically force the
>full progressive incremental backup instead
>of requiring the user to manually schedule it.
>
>For reasons that require a very detailed explanation (let me know if you
>are interested), the current snapdiff implementation
>doesn't have the robustness or resiliency that JBB does and therefore
>really requires manually scheduling full progressive
>incremental backups via the CreateNewBase option.
>
>Hope this helps ...
>
>Pete Tanenhaus
>Tivoli Storage Manager Client Development
>email: tanenhau AT us.ibm DOT com
>tieline: 320.8778, external: 607.754.4213
>
>"Those who refuse to challenge authority are condemned to conform to it"
>
>
>|------------>
>| From:      |
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>  |Paul Zarnowski <psz1 AT CORNELL DOT EDU>                                    
>                                                                              |
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> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>|------------>
>| To:        |
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>  |ADSM-L AT vm.marist DOT edu                                                 
>                                                                              |
>  
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>|------------>
>| Date:      |
>|------------>
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> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>  |02/14/2012 07:12 AM                                                         
>                                                                       |
>  
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>|------------>
>| Subject:   |
>|------------>
>  
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>  |Re: Need some support for snapdiff RFE's                                    
>                                                                       |
>  
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>|------------>
>| Sent by:   |
>|------------>
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> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>  |"ADSM: Dist Stor Manager" <ADSM-L AT vm.marist DOT edu>                     
>                                                                              |
>  
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>
>
>
>
>
>Grant,
>
>The time stamps are not updated, because a snapdiff incremental does not
>deactivate deleted files.  You need to do periodic 'createnewbase' to do
>this, which walks the file system and updates the time stamps.
>
>..Paul
>
>On Feb 14, 2012, at 12:32 AM, "Grant Street" <grants AT AL.COM DOT AU> wrote:
>
>> Hello
>>
>> Just thought I would plug two snapdiff RFE's(Request For Enhancement)
>> that I created on the IBM developer works site.
>>
>> I am trying to garner some support for these in the hope that they will
>> be implemented in the future.
>>
>> I have seen that some of you have had experience with Netapp snapdiff
>> backups and you may have similar beliefs.
>>
>> "Define snapdiff and other snap options on a per filesystem basis rather
>> than per backup command"
>> When running an incremental backup be able to define the snapdiff or
>> other snap option on a per filesystem basis rather than for the whole
>> backup incremental job.
>>
>>
>http://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=12858
>>
>> "Snapdiff to update last backup fields in filespace data"
>> Could you please update the TSM snapdiff client to update the lastbackup
>> information of filespaces when a "query filespace f=d" is issued. This
>> would be the obvious behaviour and would be inline with the documented
>> meaning of the columns
>>
>>
>http://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=13145
>>
>> TIA
>>
>> Grant


--
Paul Zarnowski                            Ph: 607-255-4757
Manager, Storage Services                 Fx: 607-255-8521
719 Rhodes Hall, Ithaca, NY 14853-3801    Em: psz1 AT cornell DOT edu