I think with COPYMODE, you are talking about how to get a complete backup
of the file system regardless of whether the files have changed, versus a
backup of changed files only. But Ken is talking about what we call "Full
incremental" versus "Partial incremental", which is different (and yes,
the terminology can be quite confusing).

"Full incremental" is a regular incremental backup with TSM, where the
client queries the server for information about existing active backup
versions, then traverses the client file systems, comparing each file's
current attributes with the attributes of that file from the server
information. If any of the attributes are different, then the file is
considered to have changed, and it is eligible for backup.

"Partial incremental" is another term for "incremental by date". In this
case, TSM just checks the date/time that the file system was last backed
up. Then it traverses the client file sysem and checks each file's
modification date/time. If the file's current modification date/time is
greater than the date/time the file system was last backed up, then the
file is eligible for backup.

The difference is that Full incremental is more thorough in checking for
changed files, at the expense of time. For large file systems, it can take
a relatively long time to get query information back from the server; plus
the client is doing more file attribute comparisons, which can also take
longer. Partial incremental is faster, but because it's checks for changed
files are less stringent, it may not capture all changed files. For
example, copying a file will produce a new file whose modification
date/time matches the original file. If this date/time is lower than the
date/time the file system was last backed up, then it won't be captured by
a Partial incremental. Also, Partial incremental doesn't expire deleted
files. So as a rule, Partial incremental is recommended only if you are
truly constrained on time for doing a Full incremental; and even then, you
should schedule a Full incremental periodically (like once a week).

Regards,

Andy

Andy Raibeck
IBM Software Group
Tivoli Storage Manager Client Development
Internal Notes e-mail: Andrew Raibeck/Tucson/IBM@IBMUS
Internet e-mail: storman AT us.eyebm DOT com (change eye to i to reply)

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




Edgardo Moso <edgardo_moso AT KINDREDHEALTHCARE DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
08/09/2002 12:35
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: Incremental Backup (full/partial)



Set copy mode parameter in the copy group to absolute for full and
modified
for incremental backup.

For partial incremental:   see manual ( ex.  by date, etc...)







From: KEN HORACEK <KHORACEK AT INCSYSTEM DOT COM> on 08/09/2002 01:36 PM

Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>

To:   ADSM-L AT VM.MARIST DOT EDU
cc:
Subject:  Incremental Backup (full/partial)

Hi fellow listers,

So here I am, "Reading the Fine Manual", and it sez; an Incremental Backup
can either be "full" or "partial"..
How can I tell if my backup(s) are requesting a "full" or "partial"
backup?

Ken
khoracek AT incsystem DOT com