The writers do not wait the time interval before they write. The writers do not flush their data buffers. However, if there is low CPU speed, high memory usage, or high input/output levels, you may experience the following behaviors:
The writers wait to write so the contents of the shadow copy will be consistent with their data buffers. Also, some Volume Shadow Copy service writers, like the Exchange writer, wait to write for a predefined time interval so the shadow copy can be created during the time interval. The inter-process calls make sure that all the important Volume Shadow Copy service writers (programs such as SQL, Exchange Server, operating system services, and others) flush their data buffers during shadow copy creation. Shadow copy creation includes a complex sequence of inter-process calls. This problem occurs especially on computers that have slow hard disks, low memory, or low CPU speed or on computers that have the disk write cache disabled (for example, on a domain controller computer).
You may experience a problem that causes certain Volume Shadow Copy service writers to time out during a lengthy shadow copy creation. Volume Shadow Copy service writer time-out The symptoms that are described earlier in this article may occur for one of the following reasons: In the message, VolumeName is the name of the volume that is scheduled for backup. Consider reducing the IO load on this system to avoid this problem in the future.
The shadow copies of volume VolumeName were aborted because the diff area file could not grow in time.