Active Administrator 8.6.3 - User Guide

DC DIT disk space

DC DIT disk space

Indicates that the amount of disk space available on the volume that Active Directory® uses for its database is less than or equal to the configured threshold.

Data collector

•	Category: General

•	Name: Active Directory database details

•	Supported on: Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, and Windows Server 2019

•	Required permissions: When monitored locally and remotely, only domain user privilege is required. When monitored remotely, the target server must have WMI remote access enabled and the user must be a member of the Distributed COM Users group.

Description

The Directory Analyzer agent monitors the disk space available on the volume containing the Active Directory database. If the amount of disk space available on this volume drops below the configured threshold for a period exceeding the configured duration, the agent sets this alert condition.

If Active Directory runs out of disk space during processing, it will eventually fail, and the server will shut down immediately.

A low disk space condition can be due to many different things, such as:

•	a user copying large amounts of data to the server for temporary storage

•	an excessively large print job in the print queue

•	an excessively large number of print jobs in the print queue

•	a widely distributed email with large attachments arriving on the server from outside

It is also possible that Active Directory may be using up more disk space than normal by importing a large number of objects into the directory through replication or by creating a large number of users or other directory objects.

The directory service agent (DSA) periodically runs a cleanup task that recovers space from deleted objects in the directory for reuse by Active Directory.

Resolution

Check the registry on the server to determine the disk volume that contains the Active Directory database. Under the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NTDS\Parameters registry key, the value DSA Database file contains the path of the file in which Active Directory keeps its database. If the Active Directory database is stored on the C: drive and this is the same drive that contains the system TEMP directory (usually C:\TEMP), delete all of the files in the TEMP directory.

Determine what directories are using the most disk space. Using Windows® Explorer, right-click on each directory and select Properties. The disk space used by the directory sub-tree will appear on the Properties page. After you determine what is causing the directories to grow, run Ntdsutil.exe to compact files, move files to another volume, or move transaction logs to another volume.

CAUTION: Use Ntdsutil with great care. Improper use of Ntdsutil can destroy directory data.

If Active Directory ran low on disk space during a server backup, the problem may be due to the space used by temporary files created by the backup process. If this is the case, you can configure Active Directory to keep its backup files on a different volume.

As a general tip, it is a good idea to put the Active Directory database on its own file volume with only Administrator access so that the disk space available to Active Directory cannot be reduced by other applications.

DC DIT log file disk space

DC DIT log file disk space

Indicates that the amount of disk space available on the volume Active Directory® uses for its log files is less than or equal to the configured threshold.

Data collector

•	Category: General

•	Name: Active Directory database log details

•	Supported on: Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, and Windows Server 2019

•	Required permissions: When monitored locally and remotely, only domain user privilege is required. When monitored remotely, the target server must have WMI remote access enabled and the user must be a member of the Distributed COM Users group.

Description

The Directory Analyzer agent monitors the disk space available on the volume containing the Active Directory log files. If the amount of disk space available on this volume drops below the configured threshold for a period exceeding the configured duration, the agent sets this alert condition.

If Active Directory runs out of disk space during processing, it will eventually fail, and the server will shut down immediately.

A low disk space condition can be due to many different things, such as:

•	a user copying large amounts of data to the server for temporary storage

•	an excessively large print job in the print queue

•	an excessively large number of print jobs in the print queue

•	a widely distributed email with large attachments arriving on the server from outside

The directory service agent (DSA) periodically runs a cleanup task that recovers space from deleted objects in the directory for reuse by Active Directory.

Resolution

First, check the registry on the server to determine the disk volume that contains the Active Directory log files. Under the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NTDS\Parameters registry key, the value Database log files path contains the path of the file in which Active Directory keeps its log files.

If you have recently deleted a large number of objects, you can reclaim disk space from the directory using Ntdsutil.exe to compact files.

CAUTION: Use Ntdsutil with great care. Improper use of Ntdsutil can destroy directory data.

DC LDAP load

DC LDAP load

Indicates that the amount of Lightweight Directory Access Protocol (LDAP) traffic serviced by the domain controller equals or exceeds the configured threshold.

Data collector

•	Category: Performance Counters

•	Name: NTDS LDAP writes a second

•	Supported on: Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, and Windows Server 2019

•	Required permissions: When monitored locally and remotely, only domain user privilege is required and the user must be a part of the Performance Logs user group.

Description

The Directory Analyzer agent monitors the NTDS LDAP writes a second performance counter on the domain controller. If the value goes above the configured threshold for a period exceeding the configured duration, the agent sets this alert condition.

Active Directory® clients use LDAP to communicate with the Directory Service Agent (DSA). A high LDAP load indicates that a lot of clients are making many requests of the DSA. Increased LDAP load can reduce the throughput of the DSA, and can cause important directory transactions, such as login and authentication, to fail.

Resolution

Identify the source of the LDAP traffic by using a network traffic analyzer. Note that a traffic analyzer will not detect the traffic generated by a process running on the domain controller itself.

•	If the majority of LDAP traffic is due to a single process, end that process or redirect it to another less loaded server.

•	If the traffic is due to many different workstations, the problem may be that there are not enough functioning domain controllers or global catalogs in the site.

DC LDAP response too slow

DC LDAP response too slow

Indicates that the response time of the domain controller to a Lightweight Directory Access Protocol (LDAP) request equals or exceeds the configured threshold.

Data Collector

•	Category: General

•	Name: LDAP response time

•	Supported on: Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, and Windows Server 2019

•	Required permissions: When monitored locally and remotely, only domain user privilege is required.

Description

The Directory Analyzer agent periodically issues a simple LDAP query to each domain controller in the site it monitors and measures the time between issuing the LDAP request and receiving a response. An alert is generated if the response time exceeds the configured threshold for longer than the configured duration.

Active Directory® clients use LDAP to communicate with the Directory Service Agent (DSA). A high response time value indicates that the domain controller is not satisfying directory requests quickly, which can result in poor client response times and, if bad enough, login and authentication failures.

Anything that could cause a reduction in overall system performance can increase LDAP response time. For instance, running too many processes, or running processes that use too much memory or CPU can reduce system performance and increase LDAP response times.

A poorly configured server can also increase LDAP response times. For instance, if the paging file is not large enough or if the disks are badly fragmented, poor disk performance can increase LDAP response time.

In some cases faulty hardware can also cause an increase in LDAP response time. For instance, a marginal Network Interface Card (NIC) can reduce network performance on the server, and a failing disk can make directory queries take a long time.

It is possible that the DSA on the domain controller is overloaded by incoming directory requests, by excessive Access Control List (ACL) propagation, or by too many complex directory queries.

Resolution

•	Determine if anything is degrading overall system performance, or if just Active Directory performance is poor.

•	Check the LDAP load on the server. If this is high, try to identify the traffic that is causing the LDAP load on the server.

•	Determine what processes are using the most CPU and generating the most disk I/O.

▪	If a single process is generating most of the load, see if that process can be run on a different server.

▪	If there are many processes using a significant amount of system resources, try to remove several of them.

▪	If Local Security Authority Subsystem Service (LSASS) is using more than its share of server resources, then something is overloading the DSA.