This Knowledgebase article provides information about unprotected features of the Windows NTFS file system.
The Microsoft Windows family of Operating Systems supports a number of features for which Neverfail for File Server does not offer protection. There are a variety of reasons for this, but in general, any feature whose presence might lead to corruption, loss of data, abnormal disk space usage, or other detrimental effects, on the passive server, is treated as an unprotected feature. Neverfail for File Server can be configured to respond to such features in a variety of ways, depending on the risk posed by each type of unprotected feature. By default, there are three responses:
AFFECTED FEATURES: Sparse files, disk quotas
EXAMPLE: Sparse Files
WARNING:
- Unprotected Feature Detected [ Primary | Secondary ] (while active)
- Sparse Files may not be replicated for the file / directory : C:\MyDirectory\SF\File1.txt.
RESULT: Neverfail Heartbeat data replication continues, but the Sparse Files referred to in the warning message may not be replicated.
RECOVERY: None required
This strategy is used where replication of file content cannot be guaranteed, or where the file system might become 'Out of Synch' due to file access or locking issues on the passive (formerly active) server after a switchover. Neverfail Heartbeat will allow data replication to continue, but marks any affected files as 'Out of Synch' in order to prevent a switchover.
AFFECTED FEATURES: Encryption, extended attributes
EXAMPLE: ENCRYPTION
ERROR:
- Unprotected Feature Detected [ Primary | Secondary ] (while active)
- Automated Out Of Synch Applied : Use of Encrypted Files has been detected for the file / directory :
C:\MyDirectory\Encrypt\EncryptFolder
As a result of this, the file/directory will be marked as Out Of Synch.
RESULT: Neverfail Heartbeat data replication continues, but the File System status is set to 'Out of Synch'. Shared folders are still available on the active server.
RECOVERY: The affected file(s)/folder(s) must be removed from the protected set to allow the file system to synchronize. Switchover will not be possible until this has been done, though failover can still take place if the active server fails. Use one of the methods below:
Note: If method 2 is used, it may be necessary to synchronize one or more files / folders manually afterwards. This can be done with the following procedure:
Please refer to Neverfail Heartbeat product documentation for further information on synchronizing files and folders.
This is used where some file metadata may not be replicated to the passive server, but in all other respects, replication can continue unhindered, and near-normal service can be expected following switchover or failover. Note that file attributes (with the exception of the Encryption flag) and file permissions are not affected in this way, and will always be replicated.
This strategy is used where data replication might lead to corruption of files on the passive server. Any subsequent switchover could corrupt the original data on the server that was active; and, in the event of a failover, there is a risk that the failed server could be recovered and reconnected in the passive role, and have its data overwritten with corrupted file content from the surviving server, now operating in the active role. The safest option here is to cease replication since, if replication is stopped, neither switchover nor failover can occur, allowing the issue to be resolved safely.
AFFECTED FEATURES: Hard links, reparse points (volume mount points, directory junctions, symbolic links, single instance store, remote storage). Note that Windows 2003 DFS Reparse Points are NOT affected, as they are fully supported by Neverfail Heartbeat from V4.3 onwards.
EXAMPLE: HARD LINKS
ERROR (1):
- Unprotected Feature Detected [ Primary | Secondary ] (while active)
- Automated Replication Stop Applied : Use of Hard Links has been detected for the file / directory :
C:\MyDirectory\HardLinkFile1
As a result of this, Neverfail Heartbeat has been stopped with the protected applications left running.
ERROR (2):
- System Stop [ Primary | Secondary ] (while active)
- Neverfail Heartbeat is stopping (without stopping the protected applications) for the following reason :
Automated Replication Stop Applied : Use of Hard Links has been detected for the file / directory :
C:\MyDirectory\HardLinkFile1
As a result of this, Neverfail Heartbeat has been stopped with the protected applications left running.
RESULT: Neverfail Heartbeat data replication stops, but shared folders are still available on the active server.
RECOVERY: The affected file(s) / folder(s) must be removed from the protected set before replication can be restarted. Use one of the methods below to accomplish this:
Method 1 (preferred)
Manually delete the filter for the file(s) / folder(s) identified in the error message.
Start replication
Using Windows Explorer, or any other suitable tool, un-share the affected folder(s) on the active server. This MUST be done while Neverfail Heartbeat is replicating. If method 2 is used, it may be necessary to synchronize one or more files / folders manually afterwards. To do this, follow the procedure below:
Note: DO NOT choose the option to synchronize subdirectories. Please refer to Neverfail Heartbeat product documentation for further information on synchronizing files and folders.
ID | Name | LogAsError | MakeOutOfSync | MaxOccurrences | RaiseStopEvent | RaiseUserEvent |
0 | Extended Attributes | True | True | 100 | False | True |
1 | Hard Link | True | False | 100 | True | True |
2 | Hard Link Mismatch | True | False | 100 | True | True |
3 | Reparse Point | True | False | 100 | True | True |
4 | Encryption | True | True | 100 | False | True |
5 | Sparse File | True | False | 100 | False | True |
6 | Disk Quota | True | False | 100 | False | True |
Windows NTFS File System
None
KBID-321