SYSVOL replication issues
Recently had a DC (we'll call it DC1) acting very strangely.
There were some errors in the event logs:
--------------------------
EventID 1058, The system cannot find the path specified. (then lists a GPO GUID path in SYSVOL)
--------------------------
Rebooting would just give me the error again. Tried gpupdate and got this:
--------------------------
C:\>gpupdate
Updating Policy...
User policy could not be updated successfully. The following errors were encount
ered:
The processing of Group Policy failed. Windows attempted to read the file \\domain.local\SysVol\domain.local\Policies\{9EA16EAF-3A76-4972-88CE-1BA2435CAE8
E}\gpt.ini from a domain controller and was not successful. Group Policy setting
s may not be applied until this event is resolved. This issue may be transient a
nd could be caused by one or more of the following:
a) Name Resolution/Network Connectivity to the current domain controller.
b) File Replication Service Latency (a file created on another domain controller
has not replicated to the current domain controller).
c) The Distributed File System (DFS) client has been disabled.
Computer policy could not be updated successfully. The following errors were enc
ountered:
The processing of Group Policy failed. Windows attempted to read the file \\domain.local\SysVol\domain.local\Policies\{9EA16EAF-3A76-4972-88CE-1BA2435CAE8
E}\gpt.ini from a domain controller and was not successful. Group Policy setting
s may not be applied until this event is resolved. This issue may be transient a
nd could be caused by one or more of the following:
a) Name Resolution/Network Connectivity to the current domain controller.
b) File Replication Service Latency (a file created on another domain controller
has not replicated to the current domain controller).
c) The Distributed File System (DFS) client has been disabled.
To diagnose the failure, review the event log or invoke gpmc.msc to access infor
mation about Group Policy results.
C:\>
--------------------------
To explain what exactly was going wrong, I must sketch out SYSVOL and GPO. SYSVOL is replicated among the DCs and contains things like logon scripts, GPOs, etc. When a GPO is applied, it's pulled from SYSVOL (simplifying things) which resides on the nearest DC. When a DC accesses it, it uses the local SYSVOL cache.
You can browse to SYSVOL's GPOs: \\domain.local\sysvol\domain.local\Policies
You'll see folders labeled with the GUIDs of all your GPOs. In this case, the GUID referenced in the error simply was not there. I checked all the other DCs and the GPO was present on them. Very odd.
I also began to notice other events, these on all other DCs except the one I started looking at: NtFrs EventID 13508, warning, trouble enabling replication between DC1 and THISDC.
Every other DC showed the same warning, so that pointed directly at DC1 being the issue. I checked into DC1's logs a little deeper this time, and came up with this: NtFrs EventID 13568
--------------------------
The File Replication Service has detected that the replica set "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)" is in JRNL_WRAP_ERROR.
Replica set name is : "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)"
Replica root path is : "c:\windows\sysvol\domain"
Replica root volume is : "\\.\C:"
A Replica set hits JRNL_WRAP_ERROR when the record that it is trying to read from the NTFS USN journal is not found. This can occur because of one of the following reasons.
[1] Volume "\\.\C:" has been formatted.
[2] The NTFS USN journal on volume "\\.\C:" has been deleted.
[3] The NTFS USN journal on volume "\\.\C:" has been truncated. Chkdsk can truncate the journal if it finds corrupt entries at the end of the journal.
[4] File Replication Service was not running on this computer for a long time.
[5] File Replication Service could not keep up with the rate of Disk IO activity on "\\.\C:".
Setting the "Enable Journal Wrap Automatic Restore" registry parameter to 1 will cause the following recovery steps to be taken to automatically recover from this error state.
[1] At the first poll, which will occur in 5 minutes, this computer will be deleted from the replica set. If you do not want to wait 5 minutes, then run "net stop ntfrs" followed by "net start ntfrs" to restart the File Replication Service.
[2] At the poll following the deletion this computer will be re-added to the replica set. The re-addition will trigger a full tree sync for the replica set.
WARNING: During the recovery process data in the replica tree may be unavailable. You should reset the registry parameter described above to 0 to prevent automatic recovery from making the data unexpectedly unavailable if this error condition occurs again.
To change this registry parameter, run regedit.
Click on Start, Run and type regedit.
Expand HKEY_LOCAL_MACHINE.
Click down the key path:
"System\CurrentControlSet\Services\NtFrs\Parameters"
Double click on the value name
"Enable Journal Wrap Automatic Restore"
and update the value.
If the value name is not present you may add it with the New->DWORD Value function under the Edit Menu item. Type the value name exactly as shown above.
--------------------------
Essentially what has happened is the SYSVOL share has become corrupt and you need to pull a new copy from the other DCs.
1. Browse to the noted location in the registry on DC1.
2. Create the new key.
3. Change the value to ‘1’.
4. Stop/start the ntfrs service (net stop/start ntfrs).
5. Note the entries in the FRS log. (13560, 13520)
6. Change the value back to ‘0’.
7. Wait for replication to complete. (13553, 13554)
8. Note success. (13516 – no longer preventing from becoming DC)
9. Note other servers are now seeing event ID 13509 (NtFrs once again has connection).
You can actually replicate the 13508/9 events yourself, just disconnect a DC for about an hour, you'll see them pop up. Reconnect and you'll see the 13509 event.
There were some errors in the event logs:
--------------------------
EventID 1058, The system cannot find the path specified. (then lists a GPO GUID path in SYSVOL)
--------------------------
Rebooting would just give me the error again. Tried gpupdate and got this:
--------------------------
C:\>gpupdate
Updating Policy...
User policy could not be updated successfully. The following errors were encount
ered:
The processing of Group Policy failed. Windows attempted to read the file \\domain.local\SysVol\domain.local\Policies\{9EA16EAF-3A76-4972-88CE-1BA2435CAE8
E}\gpt.ini from a domain controller and was not successful. Group Policy setting
s may not be applied until this event is resolved. This issue may be transient a
nd could be caused by one or more of the following:
a) Name Resolution/Network Connectivity to the current domain controller.
b) File Replication Service Latency (a file created on another domain controller
has not replicated to the current domain controller).
c) The Distributed File System (DFS) client has been disabled.
Computer policy could not be updated successfully. The following errors were enc
ountered:
The processing of Group Policy failed. Windows attempted to read the file \\domain.local\SysVol\domain.local\Policies\{9EA16EAF-3A76-4972-88CE-1BA2435CAE8
E}\gpt.ini from a domain controller and was not successful. Group Policy setting
s may not be applied until this event is resolved. This issue may be transient a
nd could be caused by one or more of the following:
a) Name Resolution/Network Connectivity to the current domain controller.
b) File Replication Service Latency (a file created on another domain controller
has not replicated to the current domain controller).
c) The Distributed File System (DFS) client has been disabled.
To diagnose the failure, review the event log or invoke gpmc.msc to access infor
mation about Group Policy results.
C:\>
--------------------------
To explain what exactly was going wrong, I must sketch out SYSVOL and GPO. SYSVOL is replicated among the DCs and contains things like logon scripts, GPOs, etc. When a GPO is applied, it's pulled from SYSVOL (simplifying things) which resides on the nearest DC. When a DC accesses it, it uses the local SYSVOL cache.
You can browse to SYSVOL's GPOs: \\domain.local\sysvol\domain.local\Policies
You'll see folders labeled with the GUIDs of all your GPOs. In this case, the GUID referenced in the error simply was not there. I checked all the other DCs and the GPO was present on them. Very odd.
I also began to notice other events, these on all other DCs except the one I started looking at: NtFrs EventID 13508, warning, trouble enabling replication between DC1 and THISDC.
Every other DC showed the same warning, so that pointed directly at DC1 being the issue. I checked into DC1's logs a little deeper this time, and came up with this: NtFrs EventID 13568
--------------------------
The File Replication Service has detected that the replica set "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)" is in JRNL_WRAP_ERROR.
Replica set name is : "DOMAIN SYSTEM VOLUME (SYSVOL SHARE)"
Replica root path is : "c:\windows\sysvol\domain"
Replica root volume is : "\\.\C:"
A Replica set hits JRNL_WRAP_ERROR when the record that it is trying to read from the NTFS USN journal is not found. This can occur because of one of the following reasons.
[1] Volume "\\.\C:" has been formatted.
[2] The NTFS USN journal on volume "\\.\C:" has been deleted.
[3] The NTFS USN journal on volume "\\.\C:" has been truncated. Chkdsk can truncate the journal if it finds corrupt entries at the end of the journal.
[4] File Replication Service was not running on this computer for a long time.
[5] File Replication Service could not keep up with the rate of Disk IO activity on "\\.\C:".
Setting the "Enable Journal Wrap Automatic Restore" registry parameter to 1 will cause the following recovery steps to be taken to automatically recover from this error state.
[1] At the first poll, which will occur in 5 minutes, this computer will be deleted from the replica set. If you do not want to wait 5 minutes, then run "net stop ntfrs" followed by "net start ntfrs" to restart the File Replication Service.
[2] At the poll following the deletion this computer will be re-added to the replica set. The re-addition will trigger a full tree sync for the replica set.
WARNING: During the recovery process data in the replica tree may be unavailable. You should reset the registry parameter described above to 0 to prevent automatic recovery from making the data unexpectedly unavailable if this error condition occurs again.
To change this registry parameter, run regedit.
Click on Start, Run and type regedit.
Expand HKEY_LOCAL_MACHINE.
Click down the key path:
"System\CurrentControlSet\Services\NtFrs\Parameters"
Double click on the value name
"Enable Journal Wrap Automatic Restore"
and update the value.
If the value name is not present you may add it with the New->DWORD Value function under the Edit Menu item. Type the value name exactly as shown above.
--------------------------
Essentially what has happened is the SYSVOL share has become corrupt and you need to pull a new copy from the other DCs.
1. Browse to the noted location in the registry on DC1.
2. Create the new key.
3. Change the value to ‘1’.
4. Stop/start the ntfrs service (net stop/start ntfrs).
5. Note the entries in the FRS log. (13560, 13520)
6. Change the value back to ‘0’.
7. Wait for replication to complete. (13553, 13554)
8. Note success. (13516 – no longer preventing from becoming DC)
9. Note other servers are now seeing event ID 13509 (NtFrs once again has connection).
You can actually replicate the 13508/9 events yourself, just disconnect a DC for about an hour, you'll see them pop up. Reconnect and you'll see the 13509 event.
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