Active Administrator 8.5 - User Guide

DC RID pool low

Generated when the available pool of relative identifiers (RIDs) on the selected domain controller is less than or equal to the configured threshold.

Each Directory Analyzer agent monitors the RID pool assigned to the domain controller. If the number of RIDs available to the server goes below the threshold configured by the administrator, the Directory Analyzer agent will issue this alert.

All security principals in the Windows NT Security Architecture are assigned a unique security ID (SID). The SID is made up of a domain identifier and a RID. RIDs are sequential numbers issued by the domain each time a new security principal (for instance a user object) is created in that domain.

Because each domain controller can create security principals, Active Directory® breaks the available range of RIDs into allocation pools that it assigns to each domain controller. Active Directory assigns one domain controller in each domain to be responsible for allocating RID pools to all of the other domain controllers in the domain; this is the RID Operations Master. When a domain controller uses up its allocation, it requests a new range from the RID Operations Master.

If a domain controller has a problem contacting the RID Operations Master, the domain controller can actually use up its entire allocation of RIDs, and be unable to create new security principals, which can result in failures when adding new users, services, and domain controllers to the domain.

Contact your Microsoft Windows support representative.

DC SMB connections

Indicates the number of Server Message Block (SMB) connections in use on the domain controller equals or exceeds the configured threshold.

The Directory Analyzer agent monitors the Server\Server Sessions performance counter on the domain controller. If the value of the performance counter goes above the configured threshold for a period exceeding the configured duration, the agent will set this alert condition.

System Message Block (SMB) is the protocol for file and print access. Whenever a client workstation accesses files or directories on a server, or whenever the workstation prints a document to a network printer, the client uses an SMB connection.

The number of SMB connections in use on a server is a rough indication of the number of client workstations that are accessing the servers. An unusually high number of SMB connections indicates a large number of clients accessing the server.

A large number of SMB connections will use some amount of memory on the server, though this is generally not a big problem. However, the inordinate number of clients accessing the server can have a negative effect on overall server performance and consequently a negative effect on directory performance as well.

Determine if the increased number of SMB connections is degrading the overall performance of the server. If the performance is being affected, you will see other alerts from Active Directory Health Analyzer, including DC LDAP response too slow, Domain controller CPU load, DC cache hits, and Domain controller page faults.

DC SYSVOL disk space

Indicates that the available disk space on the volume host SYSVOL is less than or equal to the configured threshold.

The Directory Analyzer agent monitors the disk space available on the partition containing the SYSVOL directory. If the amount of free disk space on this partition drops below the threshold set by the administrator for a period exceeding the configured duration, the agent will set this alert condition.

The SYSVOL is a directory that contains user profile information that is replicated (via File Replication Services) to each domain controller in the domain. Although the SYSVOL is not actually part of Active Directory®, a failure in SYSVOL replication can cause user login failures.

Find the directory containing the SYSVOL information by checking the registry key \\HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NetLogon\Parameters and looking at the value for the Sysvol value. This is the path of the SYSVOL directory.

If files in the SYSVOL directory are using the disk space, remove as many of these files as you can.

DC time sync lost

Indicates that the time of the target domain controller differs from one of its reference sources by more than the configured threshold (in seconds).

The Directory Analyzer agent periodically checks its local time against the configured time reference servers. If the time is off by more than the configured threshold (in seconds), the alert is raised.

The Windows® Time (W32Time) service on a domain controller is responsible for maintaining the accuracy of the clock with respect to the time sources. Active Directory® defines rules for time sources as follows:

A special case exists for the PDC Role Owner in domains that are at the root of the forest but are not the root domain (the root domain being defined as the first domain ever created in the forest). These domain controllers synchronize themselves to the PDC Role Owner in the root domain.

Any domain controller can have these settings overridden by configuring the domain controller to synchronize with an external time source using the Net Time command. If the domain controllers are so configured, then the Directory Analyzer agent will check the time against the configured external time source(s).