When attempting to open a file on a Replica host, such as a pdf or word document, to validate that the replication completed without errors the document application (Word, Acrobat reader... etc) displays an error that the file is corrupt and unreadable. While this might seem to be that the data set is corrupted on the Replica this is not the case if the Master root directory is part of a Symantec Enterprise Vault archiving configuration that replaces the content on the local disk with place holder (stub file) during its archival.
The reason the file on the Replica appears corrupt is that during normal replication in the forward or backwards direction the stub (placeholder) files will be of no use on the Replica server until that machine assumes the Hostname of the Master server and has the 'Symantec FSA agent' installed. This is accomplished with a “Switch Computer Name” (with reboot) method of Network Traffic Redirection within the CA ARCserve RHA File Server HA scenario.
This can be overcome temporarily by un-checking the box 'Ignore Same Size / Modification Time' during synchronization but this creates a completely new issue in that during synchronization the CA ARCserve RHA engine will be required to open every file on the Master host which will cause the file placeholders to be replaced with the actual data during synchronization. This means that the amount of data that will lie on disk on the Replica and Master host could far exceed that of the available space due to the archival nature of the files.
So it is recommended to perform scenario synchronization for your File Servers that contain the placeholder files for Symantec Enterprise Vault archiving to always use run with the method of “File Synchronization” with “Ignore Same Size / Modification Time” checked. This will prevent the files on the Master from being opened and repopulated onto the Master storage from archive.
You can check the files that lie on disk on the Replica to determine if they are placeholder files by right-clicking in Windows Explorer and clicking on Properties. You should find the file 'Size' compared to the 'Size on Disk' to be quite different, where the size on disk will be a few KB in size due to the nature of placeholders.
The true solution for this issue is the following:
- Install the 'Symantec FSA agent' on the Replica host but do not add this machine to any archive policies.
- When creating the CA ARCserve RHA File Server scenario make sure to choose to perform a 'Switch Computer Name (with reboot)' option for Network Traffic Redirection method
- Make sure that when starting a scenario and 'Run after reboot' properties have the default method of Synchronization set to 'File Sychronization' with 'Ignore Same Size / Modification Time' option turned ON or CHECKED.
- Understanding that the files on disk on the Replica host will not be readable until the Replica assumes the HOSTNAME of the Master host after a RHA scenario switchover has occured. *** NOTE: Only then with the files rehydrate the data from the archive database and allow the file to be opened and verified ***
Below are the Symantec Enterprise Vault knowledge base articles for reference as to why the above solution is needed.
What is a Placeholder?: http://www.symantec.com/connect/blogs/what-placeholder
How to move File System Archiving (FSA) to a new server with the same name: http://www.symantec.com/docs/TECH73261
How to move Placeholders from one Server to a new Server: http://www.symantec.com/docs/TECH68672
Placeholders fail to recall and Event ID 20491 is reported on the file server: http://www.symantec.com/docs/TECH50661