I have a 3 node windows 2016 file cluster with shared storage and using storage replica. As part of our backup strategy we leverage shadow copies to present users the ability to restore previous versions.
In windows 2016 it appears that by default we have a maxshadowcopies reg key set to 512 shadow copies, which is fine however when going to restore previous version the max displayed is 500 starting with the oldest, meaning the 12 newest shadow copies are not displayed when the user or the admin go to restore previous versions.
I tested this in several ways, one being to let the schedule take the next shadow copy and seeing the oldest being deleted and in the restore previous versions seeing the newest go up by 1 hour but lagging behind in 12.
In order for the newest previous versions to be available i have had to limit the MaxShadowCopies regkey to 500 so that the newest is always available for user or admin to restore from going through the restore previous versions.
Before the regkey change which was set to 512 MaxShadowCopies but the previous version only showing 500, and as you will notice there is none for Today.
After the regkey change and i set mine to 498 because i had deleted shadow copies manually and was at 499 so i wanted to see if the regkey took effect and next schedule and it reflected as per below.
At this point as i reflect on this i believe this to be a windows bug since the shadow copies and restore previous versions should match up to whatever the maxshadowcopies is but they do not. Hopefully someone at MS will see this and recognize and address.
Thanks
Carlos