Hello,

The fixtests for this problem are now available for download from the FTP
site.

Please note that the original note I sent out earlier erroneously stated
that the version 4.1 fixtest was 4.1.1.17 and the file names to download
begin wtih IP22088_17. In fact, the fixtest version is 4.1.1.16 and the
file names begin with IP22088_16. The 3.7 fixtest was reported correctly as
being version 3.7.2.17 and the file names beginning with IP21933_17. I have
included the corrected version of the original note below for your
reference.

The files are located on our anonymous ftp site, ftp.software.ibm.com:

Version 4.1.1.16:

Directory
/storage/tivoli-storage-management/patches/client/v4r1/Windows/v411/single

Please review the IP22088_16_readme.ftp file for information on downloading
and installing the fixtest.



Version 3.7.2.17:

Directory
/storage/tivoli-storage-management/patches/client/v3r7/Windows/v372/i386/single

Please review the IP21933_17_readme.ftp file for information on downloading
and installing the fixtest.



Andy

Andy Raibeck
IBM/Tivoli
Tivoli Storage Manager Client Development
e-mail: [EMAIL PROTECTED]
"The only dumb question is the one that goes unasked."

IMPORTANT - PLEASE READ THE FOLLOWING:

A problem with the switch between Daylight Savings Time (DST) and Standard
Time (STD) has just been discovered for the Windows TSM clients.



BACKGROUND

When Windows NT and 2000 systems automatically switch between DST and STD,
the time attributes for files stored on NTFS file systems will be shifted
by one hour. This is because NTFS displays time information as an offset
from Greenwich Mean Time (GMT). Thus when the DST change is made, the
offset from GMT is changed, causing the timestamps on your NTFS files to
also change. (Note: Time information for Event Viewer events is affected in
the same manner, but that is not pertinent to this discussion.) Further
information on this subject is available in the Microsoft Knowledge Base,
item Q129574. If you point your web browser to Microsoft's MSDN site,
http://msdn.microsoft.com, and search on "Q129574" (without the quotes),
you will find the information.



THE PROBLEM

When the system automatically adjusts between DST and STD, the TSM 3.7.2
(and higher) clients will see that the modification time has changed for
all files on NTFS systems, and will proceed to back everything up
accordingly, even if the file has not really changed. This will occur only
once after the time change, and thereafter incremental backups will proceed
as normal. However, this will almost certainly affect the amount of data
backed up by each client, effectively causing a full backup on all NTFS
file systems. This could have a large impact on network and TSM server
resources.

The following bullets summarize the conditions under which this problem can
occur:

- TSM client is running on Windows NT 4.0 or Windows 2000. TSM clients
running on Windows 9x-based operating systems (Windows 95, 98) are not
affected.

- The TSM client level is 3.7.2.x or higher (including all 4.1.x levels).
TSM client levels below 3.7.2.x are not affected, as the problem was
introduced in the 3.7.2.x code.

- The file systems are formatted for NTFS. FAT and FAT32 file systems are
unaffected by this problem.

- The operating system's time zone settings are configured to automatically
adjust for DST. You can check this by right-clicking on the Windows task
bar and selecting the "Adjust Date/Time" item in the pop-up menu.
(Alternatively, you can double-click on the clock display in the task bar.)
Either of these actions will bring up the "Date/Time Properties" dialog.
Click on the "Time Zone" tab and you should see the "Automatically adjust
clock for daylight saving changes" checkbox. If the box is checked (the
default installation setting), then your system is configured to
automatically adjust for DST. Users in regions that do not observe DST
(such as Arizona) will be unaffected by this problem, provided that the
system's time zone settings are similarly configured to not observe DST.



WHAT IBM/TIVOLI IS DOING ABOUT THIS

Here are the actions that we are taking or have taken to date:

1) We have opened a severity 1 APAR, IC28544, to address this problem.

2) We have designed and built fixtests for the 3.7.2 and 4.1.1 Windows
clients. The fixtest version numbers are 3.7.2.17 and 4.1.1.16. The
fixtests should be available in a little while. They will be posted to the
anonymous FTP server ftp.software.ibm.com in the following locations:

Version 4.1.1.16:

Directory
/storage/tivoli-storage-management/patches/client/v4r1/Windows/v411/single

Package name start with: IP22088_16


V3.7 PTF 2:

Directory
/storage/tivoli-storage-management/patches/client/v3r7/Windows/v372/i386/single


Package name starts with: IP21933_17


A follow-up note will be posted when the fixtests are actually available
for download.

3) Even with the availability of a fixtest, most customers will be unable
to roll it out in time for the time change. We have documented
circumventions for this problem (see below), as the DST to STD switch is
this weekend.

4) We are working on notifying all of our customers in the most expedient
manner possible.

5) We are continuing our escape and root-cause analyses in order to prevent
this kind of problem from happening again.



CIRCUMVENTIONS

Here are the known circumventions available thus far:

1) Lock all client nodes to prevent access to the TSM server. After the
fixtest has been applied to each system, unlock that system's node(s).
Since many nodes may be affected, a batch script may be helpful in
facilitating the locking and unlocking of the nodes.

2) If the fixtest can not yet be applied, consider using the -INCRBYDATE
option to back up the clients. The easiest way to do this is to add it to
existing schedules' options setting via the UPDATE SCHEDULE administrator
command. Example:

UPDATE SCHEDULE STANDARD DAILY OPTIONS="-INCRBYDATE"

or if your schedule already contains options, such as -SUBDIR=YES:

UPDATE SCHEDULE STANDARD DAILY OPTIONS="-INCRBYDATE -SUBDIR=YES"

Please refer to the Tivoli Storage Manager Administrator's Reference for
further information on the UPDATE SCHEDULE command.

Please refer to the Tivoli Storage Manager for Windows Using the Windows
Backup-Archive Client for further information on the -INCRBYDATE option.

3) Same as #1 above, except instead of locking each node, disable all
client sessions on the TSM server. This is easier than having to lock and
unlock each node, but would require that all affected systems have the
fixtest applied before re-enabling the server for client sessions.

4) Shut down your TSM server(s) until all affected systems can have the
fixtest applied.

5) If the additional network and TSM server overhead is not a concern, you
can just let the backups run to completion. However, because this can cause
unchanged files to be backed up, the oldest version of each affected file
will be expired. In order to avoid premature expiration, you may wish to
add '1' to each backup copygroup's VEREXISTS setting. For example, if
VEREXISTS is currently set to '15', you may wish to change it to '16'. Use
the UPDATE COPYGROUP and ACTIVATE POLICYSET commands to implement this
change. Example:

UPDATE COPYGROUP STANDARD STANDARD STANDARD STANDARD VEREXISTS=16
ACTIVATE POLICYSET STANDARD STANDARD

Please refer to the Tivoli Storage Manager Administrator's Reference for
further information on the UPDATE COPYGROUP and ACTIVATE POLICYSET
commands.



We apologize for the inconveniences caused by this problem.

Sincerely,

Andy Raibeck

IBM/Tivoli
Tivoli Storage Manager Client Development
e-mail: [EMAIL PROTECTED]
"The only dumb question is the one that goes unasked."

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