Insufficient history was present in the Change Journal

SureSync uses the NTFS Change Journal to minimize the need for directory scanning. The first time a job is run, a full scan is performed to identify any files that need to be synchronized.

Once the initial full scan is complete, the job will begin to use the NTFS Change Journal to detect changes that occur. As SureSync processes Change Journal records, it maintains a checkpoint to keep track of the last record it has read.

The "insufficient history was present in the Change Journal" message indicates that the checkpoint the SureSync job is looking for is no longer in the Change Journal. When this happens, the job must assume that events could have been missed and trigger a full scan.

The Change Journal is a first in, first out system. It will write a record into the journal and old records will be purged off the end when the journal is full. If a volume has a high level of activity, it will require a larger Change Journal than a volume that has little activity.

It's important to note that SureSync will increase the size of the Change Journal on a machine if it finds that it is too small. This can help prevent the issue from occuring again in the future.

This message will happen primarily in two situations:

• A Schedule or Real-Time Monitor has been on hold for a long period of time. For example, if you put a Schedule on hold for a week and the Change Journal only contained 4 days of history, this message would occur on the next execution of the Schedule and a full scan would be performed.
• A path is offline for a long period of time. This causes the same potential issue as a Schedule or Real-Time Monitor being on hold for a long time. If the path is offline longer than the amount of history, this can occur.

The message is harmless other than the fact that a full scan is required.