dcdiag test of domain controller
The test
If all is well this powershell command should produce no output.
dcdiag | sls -pattern "failed|error" -Context 2
If you get "failed test DFSREvent"
This is what the error looks like:
> There are warning or error events within the last 24 hours after the
SYSVOL has been shared. Failing SYSVOL replication problems may cause
Group Policy problems.
> ......................... PDCSRV failed test DFSREvent
Usually you get such errors because DC2 is not available (e.g. because it started after PDCSRV).
A) THE BEST OPTION is to run a DFS Replication Health Diagnostic
You start it like this:
Start

, select Replication

click

and Next, Next, ...
If the health report looks like this (0 errors, all servers reporting) you are OK:

B) ALTERNATIVELY IF YOU WANT to check the errors then use these 2 commands:
FIRST A PLAIN TEXT VIEW WITH THE ERRORS (only keeping the most important data for each event)
$Yesterday = (Get-Date) - (New-TimeSpan -Day 1)
Get-Eventlog -LogName 'DFS Replication' -After $Yesterday | ? {($_.EntryType -Match "Error")}
| Select -Property Message,Source,TimeGenerated | fl
#\____________________________________/ \_______________/ \_______________________________/ \___________________________________________/ \____________
#get the event logs from DFS-R subsystem last 24hrs only keep only Errors keep only these properties of each event format as list
THEN A GUI VIEW (including warnings and
all event data -- you can filter them out easily):
$Yesterday = (Get-Date) - (New-TimeSpan -Day 1)
Get-Eventlog -LogName 'DFS Replication' -After $Yesterday | where {($_.EntryType -Match "Error") -or ($_.EntryType -Match "Warning")}
| ogv