Daylight Savings Time Changes Causes Conflicts in Xchange Agents and File Transfers - Search Again SUMMARY After the change to Daylight Savings time, all of my files have shifted by one hour on my computer. Now if I try to run my Xchange Agent, I see many conflicts. Is there anything I can do to automate resolving the conflicts? How do I make certain that I do not lose any data? CAUSE A number of different factors are responsible for this problem.
Some system BIOS adjust the computers built-in real-time clock to compensate for daylight savings time automatically. Windows NT and Windows 2000 can also adjust for daylight savings time. If both the BIOS and Windows NT adjust the clock for daylight savings time, your clock will be one hour off. Windows NT updates its internal date and time every hour by reading the CMOS on the motherboard. In-between the one hour intervals, Windows NT/2000 increments its own clock approximately every 10 milliseconds. Because Windows NT/2000 cannot detect when the system BIOS/CMOS (hardware level) adjusts the clock for daylight savings time, it may change the clock by one hour, just as the BIOS does. This causes your computer clock to be one hour ahead in the Spring or one hour behind in the Fall after both your computer's BIOS and Windows NT/2000 adjust the clock for daylight savings time. This also occurs if your system dual boots under Windows 95/98 and Windows NT/2000, since both operating systems will adjust for daylight savings time independently, also causing the clock to be off by an hour.
Windows NT and 2000 write date/time file information in Greenwich Mean Time (GMT) to the NTFS file table, then changes the information displayed by applying time zone adjustments and daylight savings time adjustments as needed. Windows 95 and 98 do not adjust the time returned from the file system for Daylight Savings Time. This feature was included by design, to allow Windows 95 to work with networks servers such as Novell NetWare that did not support the Daylight Savings time APIs and time functions in Windows 95. In this case, the files will display off by one hour.
The net result is that files on different systems may report time stamps differently, depending on what their time zone settings and daylight savings settings are for their CMOS and Windows clocks. These changes cause LapLink to see conflicts where none may exist, and may cause LapLink to copy a slightly older version of a file over a newer version.
LapLink records the date and time in the Agent file when it runs. This gives LapLink a baseline to compare against, so that only the files with changed date/time stamps are included. The Xchange Agent interprets all files as changed because Daylight Savings Time changes the file date/time stamps. Additionally, if one computer changes the time stamps differently from the other, it will cause the same files to appear newer on one computer, whether or not the files are different.
SOLUTION Unfortunately, a single solution does not exist. The critical decision is whether the data in the files has actually changed since the last time the Xchange Agent ran. If you are uncertain, the safest decision is to resolve the conflicts individually. You may need to open the data files to determine which file is actually the most recent. While this is time-consuming, it is the best way to insure that the data is not lost.
If the conflicts are created solely because of the change in the BIOS and Windows system clocks, then the best solution is to temporarily modify the Xchange Agent to run unattended, resolving all conflicts by copying the file with the later date/time stamp over the earlier one. This is a good solution only if you are certain that the actual data in the files is unchanged. You can do this as follows:
- From LapLink's SyncTools menu, click Open Xchange Agent.
- Click the Xchange Agent you wish to modify and click Open. This opens the Xchange Agent edit screen.
- From the Xchange Agent's File menu, point to Properties and click the Run Options tab.
- Click to select Run unattended, without preview or confirmations.
- Two choices are given for how to resolve conflicts. If you are certain that no data has changed in the files but the date stamps, then click to select Copy the newer files over the older.
- Click Apply, then OK.
- From the File menu, click Save Xchange Agent.
- You can now run the agent to sync up the date-time stamps, between the computers. When completed, just return to Step 5 again and change to the level of preview and confirmation you wish to use.
Note: This will not prevent conflicts if the Xchange Agent is set to transfer files in a single direction and the files on the target machine have a later date/time stamp than on the source computer. In that case, you will need to run a SmartXchange file transfer, as described below.
Using SmartXchange
If the files on the target computer have a later date/time stamp than the source computer and you know the data is identical on both computers, you will need to use SmartXchange to manually synchronize. This will be required only once. After that, use the Xchange Agent as before.
To synchronize the file date/time stamps using Smart Xchange,
- Open LapLink and make the File Transfer connection to the other computer.
- On the source computer, click to highlight the first folder pair to be transferred.
- Click the SmartXchange icon. This will first move all newer stamped files from the source computer to the target, then do the same from target back to source. If SpeedSync is in use, the actual contents of any files that are identical will not be transferred, only the date-time stamps will be changed.
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