Daylight Savings Time Changes Causes Conflicts in Xchange Agents and File TransfersLast updated on April 6, 2012
Document relates to: Laplink Gold (All versions), PCsync, Switch & Sync
After the change to or from Daylight Savings Time, I see many conflicts when I run my saved Xchange Agent. Why is this? Is there anything I can do to automate resolving the conflicts? How do I make certain that I do not lose any data?
Laplink records the current 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 then interprets each of the file date/time stamps based on what the Windows File System reports to it; which can be reported differently based on the factors below:
The Date & Time stamp of each file has been altered after the change to Daylight Savings Time.
Windows NT, 2000 and XP, Vista and 7 report Date/Time file information from the NTFS file table differently than from older file systems (FAT & FAT32). When the daylight savings time takes affect, Windows adjusts the Date/Time stamp on NTFS file systems based on the current local time’s offset from UTC (Universal Coordinated Time). Windows does not adjust the Date/Time stamp for FAT & FAT32 partitions. Therefore, when the file systems on the computers are different, they may report time stamps differently after the change to Daylight Savings Time. This causes Laplink to see conflicts where none may exist.
For a more detailed explanation of how time & date stamps are reported differently by different file systems, see the following document from Microsoft’s Knowledge Base.
NOTE: This problem will not occur if both computers use the same file system. Windows NT, 2000 and XP can use any file system, though Win95/98/ME operating systems cannot use NTFS.
Windows Clock is off by one hour after the change to Daylight Savings Time.
Any time that the Windows Clock differs significantly between guest & host computers, the possibility of synchronization conflicts exist. This will cause the same files to appear newer on one computer, whether or not the files are different. This behavior will occur regardless of operating systems.
Occasionally, the system BIOS as well as Windows NT can simultaneously update the clock. This can result in a duplicated time change update. More information about this problem can be found here in the Microsoft Knowledge Base.
1) If you are certain that the data in the files has not changed since the last time you ran the Xchange Agent, then the most efficient workaround is to temporarily modify the Xchange Agent to run unattended and resolve all conflicts automatically by copying the newer files over the older. After you run this Xchange Agent the date-time stamps for the files will once again be in sync. The steps for doing this are 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, return to Step 5 to change back to the desired level of preview and confirmation.
If you do not wish to temporarily reconfigure your Xchange Agent(s), you may use the Smart Xchange to manually force a synchronization. This will be required only once. After that, you may use the Xchange Agent as before.
To synchronize the file date/time stamps using Smart Xchange,
- Open Laplink/PCsync 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 Smart Xchange 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.
2) If you are uncertain whether or not the data has changed, then the safest course of action is to manually resolve each conflict. You may need to open up each data file to determine which file is the most recent. While this is time-consuming, it is the safest way to ensure that no data is lost. Alternatively, you can move the data that you suspect contains actual changes into a temporary folder in order to isolate it, and then perform the automatic conflict resolution as described above.
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Keywords: File Transfer: Xchange Agent, Xchange Agent: Error messages, Xchange Agent: Scheduler
Platforms: Win95, Win98/SE, WinNT, WinMe, Win2K, WinXP, WinVista, Win7