There are seven service types, and you can find an explanation of each (along with the other parts of a service unit file) in the systemd.service(5) man page. (You can also find more information in the resources at the end of this article.)
It is, however, recommended that you run systemctl daemon-reload after changing a unit file or creating a new one. This notifies systemd that the changes have been made, and it can prevent certain types of issues with managing altered services or units. Go ahead and run this command.
The since specification skips all of the entries before that time, but there are still a lot of entries after that time that you do not need. You can also use the until option to trim off the entries that come a bit after the time you are interested in. I want the entire minute when the event occurred and nothing more:
There is a great deal of information about systemd available on the internet, but much is terse, obtuse, or even misleading. In addition to the resources mentioned in this article, the following webpages offer more detailed and reliable information about systemd startup.
Opensource.com aspires to publish all content under a Creative Commons license but may not be able to do so in all cases. You are responsible for ensuring that you have the necessary permission to reuse any work on this site. Red Hat and the Red Hat logo are trademarks of Red Hat, Inc., registered in the United States and other countries.
Possible failure while deleting $DiskAlias from the source Storage Domain $StorageDomainName during the move operation. The Storage Domain may be manually cleaned-up from possible leftovers (User:$UserName).
Host $VdsName does not comply with the cluster $ClusterName Random Number Generator sources. The Hosts supported sources are: $hostSupportedRngSources; and the cluster requirements are: $clusterRequiredRngSources.
Windows Event Log captures system, security, and application events on Windows operating systems.It serves as a repository of detailed events generated by the system and is the first resource IT administrators refer to when troubleshooting issues.Besides resolving problems, Windows events are also used to monitor, analyze, and satisfy compliance mandates.
Unlike other event logs, such as the UNIX syslog, Windows Event Log is not stored as a plain text file but in a proprietary binary format.Therefore, it is impossible to view the logs in a text editor or send them as syslog messages while retaining their original format.However, the raw event data can be translated into XML using the Windows Event Log API.
Windows has stored Windows Event Log files in the EVTX file format since the release of Windows Vista and Windows Server 2008.Before that, event log files were stored in the EVT file format.Both are proprietary formats readable by the Microsoft Management Console (MMC) snap-in eventvwr.msc.
The EVTX format has many enhancements over its predecessor, including new event properties, the use of channels to publish events, a new Event Viewer, a rewritten Windows Event Log service, and support for the Extensible Markup Language (XML) format.From a log collection perspective, the added support for XML is the most important feature since it allows sharing or processing of event data in a structured format.
You can switch to the Friendly View by clicking on the Details tab.This view shows a hierarchical list of standard and event-specific properties.It does not show the descriptive message from the event template.
Serviced channels are relatively low volume and offer reliable event delivery.Event collectors can subscribe to these channels, and you can forward events from them to another system.
Direct channels are for high-performance event collection and are disabled by default.It is not possible to subscribe to a direct channel.To see these channels in Windows Event Viewer, enable Show Analytic and Debug Logs in the View menu.To enable logging for a direct channel, right-click on it and select Properties, then check the Enable logging option on the General tab.
The im_msvistalog module is available on Windows only and captures event log data from Windows 2008/Vista and later.It can collect events locally or from a remote system via MSRPC (NXLog Enterprise Edition only).See Local Windows log collection with im_msvistalog and Remote Windows log collection with im_msvistalog.
The im_wseventing module is available on both Linux and Windows (NXLog Enterprise Edition only).It can receive event log data from remote Windows systems via Windows Event Forwarding.We recommend this module for remote log collection because of the ease of configuring WEF clients through GPO.See Remote Windows log collection with im_wseventing.
NXLog Enterprise Edition can collect events from remote Windows systems with the im_msvistalog module.In this mode, you do not need to install the NXLog agent on each Windows system; instead, a central agent collects the events from them via MSRPC.
The module retrieves the available log sources from the SYSTEM\CurrentControlSet\Services\Eventlog registry key and polls logs from all the sources.You can also specify the sources from which you want to collect logs with the Sources directive.
NXLog Enterprise Edition provides the im_wseventing module for receiving Windows event logs from remote machines via Windows Event Forwarding (WEF).You can use this module on both Windows and Linux hosts.
You can filter for specific hosts by adding the tag to the QueryXML block.This tag expects a pattern that NXLog will match against the name of the connecting Windows client.If the computer name does not match the specified pattern, NXLog will not collect its events.
Applications and services on Windows can generate a large volume of logs, and it is often necessary to collect a subset of the events.There are several ways to filter events from the Windows Event Log using the im_msvistalog module.
You can specify an XPath query with the Query or QueryXML directives.An XPath query allows you to subscribe to multiple channels and filter events by various attributes.However, XPath queries have a maximum length, limiting the possibilities for detailed event subscriptions.See XPath filtering below.
You can process a log file with the File directive, in which case im_msvistalog will read all events from the .evtx file.This method is intended primarily for forensics, for example, using the nxlog-processor to process historical data.
Subscribing to a restricted set of events with an XPath query provides a performance advantage because NXLog will not collect unnecessary events in the first place.However, XPath queries have a maximum length and limited filtering capabilities, so you may need to combine XPath filtering with post-collection processing.For examples, see Example monitoring configurations in Event IDs to Monitor.
Windows Event Log supports a subset of XPath 1.0.You can use XPath queries to subscribe to events matching specific criteria, both in Windows Event Viewer and with the im_msvistalog QueryXML directive.For more information, see Consuming Events on Microsoft Learn.
You can enable advanced filtering by selecting the Edit query manually checkbox on the XML tab.We recommend verifying that the query matches the correct events before copying it to the NXLog configuration.
When dealing with thousands or millions of events, processing and storing this data for every event unnecessarily increases the network load and storage requirements.Removing descriptive messages and other unnecessary information can reduce the amount of data by half, helping to drive down costs related to network bandwidth and disk space, and making a substantial difference for SIEMs that charge by the amount of ingested data.
The im_msvistalog module populates the $Message field with the entire event message, including any descriptive text.If your SIEM accepts unstructured data, such as Syslog or Snare format, NXLog uses this field to format the output data.However, the event descriptions are usually not required by SIEMs and can be removed to reduce the event size significantly.For example, the following table shows data for a sample event with ID 4624 in Syslog format.
SIEMs capable of ingesting structured data are often pre-loaded with standard event information, such as the event type, category, and severity, mainly for security events.Therefore, fields like the $TaskValue, $Opcode, and $OpcodeValue can be removed before forwarding.In addition, for SIEMs that do not require the original event message, the $Message field can also be removed since it is redundant.The following table contains data for a sample event with ID 4624 in JSON format.
This xm_pattern pattern file compares Windows security events based on the event ID.Each rule defines an Exec block so that the description is removed from the $Message field for each matching event.You can also define regex patterns for a more generic configuration; however, regex patterns are not as efficient as exact patterns and may delay log processing if used excessively.See the xm_pattern documentation for an example.
One of the most challenging tasks regarding Windows log collection is deciding which event IDs to monitor.Due to the sheer number of event IDs, this can be daunting at first sight.Therefore, this section will guide you in selecting the event IDs to monitor, and provide example configurations for collecting them.
d0d94e66b7