vnx-timeservices

EMC VNX SeriesRelease 7.0

Configuring Time Services on VNXP/N 300-011-813

REV A01

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Published February 2011

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2 Configuring Time Services on VNX 7.0

Contents

Preface.....................................................................................................5

Chapter 1: Introduction...........................................................................9System requirements.............................................................................................10

Cautions..................................................................................................................10

User interface choices...........................................................................................10

Related information..............................................................................................11

Chapter 2: Concepts.............................................................................13NTP..........................................................................................................................14

SNTP........................................................................................................................14

Time distribution...................................................................................................14

Select NTP servers.................................................................................................15

Clock adjustment...................................................................................................16

Time zones..............................................................................................................16

Time services..........................................................................................................17

Chapter 3: Configuring.........................................................................19Start Data Mover time services............................................................................20

Start time services Example 1...............................................................20



Verify the time services configuration................................................................22

Chapter 4: Managing............................................................................23Set the Data Mover system time..........................................................................24

Update the Data Mover system time..................................................................24

Configuring Time Services on VNX 7.0 3

Stop Data Mover time services............................................................................24

Delete a Data Mover time services configuration.............................................25

View Data Mover time services statistics...........................................................25

Set the Data Mover time and date manually.....................................................26

Display the current time and date for the Data Mover....................................27

Set a time zone by using the POSIX-method.....................................................28

Verify the time zone....................................................................................28

Set a time zone by using the Linux method......................................................29

Chapter 5: Troubleshooting..................................................................31EMC E-Lab Interoperability Navigator..............................................................32

Diagnose problems................................................................................................32

Error messages.......................................................................................................33

EMC Training and Professional Services...........................................................33

Appendix A: Windows Domain Controller as a Time Server..............35Configure a domain controller as a time server................................................36

Appendix B: Control Station as a Time Server....................................39Create an NTP configuration file........................................................................40

Start Control Station time services......................................................................40

Stop Control Station time services......................................................................41

Disable Control Station time services automatic restart..................................41

Enable Control Station time services automatic restart...................................42

Verify a Control Station time services configuration.......................................43

Synchronize the Data Mover time services.......................................................44

Glossary..................................................................................................45

Index.......................................................................................................47


Contents

Preface

As part of an effort to improve and enhance the performance and capabilities of its product lines,EMC periodically releases revisions of its hardware and software. Therefore, some functions describedin this document may not be supported by all versions of the software or hardware currently in use.For the most up-to-date information on product features, refer to your product release notes.

If a product does not function properly or does not function as described in this document, pleasecontact your EMC representative.


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EMC support, product, and licensing information can be obtained as follows:

Product information For documentation, release notes, software updates, or forinformation about EMC products, licensing, and service, go to the EMC Online Supportwebsite (registration required) at http://Support.EMC.com.

Troubleshooting Go to the EMC Online Support website. After logging in, locatethe applicable Support by Product page.

Technical support For technical support and service requests, go to EMC CustomerService on the EMC Online Support website. After logging in, locate the applicableSupport by Product page, and choose either Live Chat or Create a service request. Toopen a service request through EMC Online Support, you must have a valid supportagreement. Contact your EMC sales representative for details about obtaining a validsupport agreement or with questions about your account.

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Preface

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Preface


Preface

1Introduction

Time services configuration is one of the basic tasks that you must performto ensure the correct operation of VNX. This document describes how toconfigure and use time services on the Data Movers in VNX. VNX SystemOperations describes how to set the time zone for the system and how tomanually set the current date and time on the Control Station.

This document is part of the VNX documentation set and is intended foruse by the system administrators responsible for configuring andmaintaining the file storage and network retrieval infrastructure. Thissection includes some terminology and restrictions that you should befamiliar before configuring or modifying network settings.

Topics included are:

System requirements on page 10 Cautions on page 10 User interface choices on page 10 Related information on page 11


System requirements

Table 1 on page 10 describes the EMC VNX software, hardware, network, and storageconfigurations.

Table 1. System requirements

VNX 7.0.Software

No specific hardware requirements.Hardware

To use NTP with VNX, at least one NTP server on the network must be accessible to the file server.To use the Control Station as a time server for the Data Movers, time services must be configured andstarted on the Control Station.

Network

No specific storage requirements.Storage

Cautions

If any of the following information is unclear, contact your EMC Customer SupportRepresentative for assistance:

Do not use the Control Station as time server for the Data Movers in the VNX system.Use standard time servers for all clients and services whenever possible.

If you have configured time services on the Data Movers to use the Control Station asthe only time server, either stop time services on the Data Movers or configure additionaltime servers on the Data Movers before stopping the time service on the Control Station.

User interface choices

VNX offers flexibility in managing networked storage that is based on the supportenvironment and interface preferences. This document describes how to configure VNXtime services by using the command line interface (CLI). You can also perform some of thesetasks using one of the following VNX management applications:

EMC Unisphere

Microsoft Management Console (MMC) snap-ins

Active Directory Users and Computers (ADUC) extensions

The following documents provide additional information about managing your VNX:

Unisphere online help

Applications online help system in the VNX Documentation on EMC Online Support


Introduction

Installing VNX Management Applications includes instructions on launching the Unispheresoftware, and on installing the MMC snap-ins and the ADUC extensions.

Related information

The following documents provide specific information related to the features andfunctionality described in this document:

EMC VNX Command Line Interface Reference for File

VNX System Operations

Configuring and Managing Networking on VNX

VNX for File man pages

EMC VNX documentation on the EMC Online Support website

The complete set of EMC VNX series customer publications is available on the EMCOnline Support website. To search for technical documentation, go tohttp://Support.EMC.com. After logging in to the website, click the VNX Support byProduct page to locate information for the specific feature required.

Related information 11

Introduction


Introduction

2Concepts

The Network Time Protocol (NTP) and Simple Network Time Protocol(SNTP) provide the mechanism for keeping the current time synchronizedon multiple systems in a network. A hierarchical structure of time serversdistributes a timestamp, which the clients use to adjust their system time.The time distributed by the servers is expressed in coordinated universaltime (UTC) and is independent of the clients and servers time zone. Thenetwork data format is identical for NTP and SNTP.

The Data Mover implements an NTP client that can synchronize the systemclock with that of an NTP or SNTP server. In all commands and in theremaining part of this document, the term NTP server is used to refer toeither NTP or SNTP servers.

For many applications to work correctly, the client and server time mustbe approximately the same. For example, Kerberos that is supported inWindows and certain UNIX environments, requires all clients and serversto be synchronized to within at least five minutes.


NTP on page 14 SNTP on page 14 Time distribution on page 14 Select NTP servers on page 15 Clock adjustment on page 16 Time zones on page 16 Time services on page 17


NTP

NTP is a standard time-keeping protocol used on many platforms that include MicrosoftWindows and UNIX environments. The full NTP specification uses sophisticated algorithmsfor time correction and maintenance to allow time synchronization with an accuracy ofabout a millisecond. This high level of accuracy is achieved even in large networks withlong network delays, or in cases where access to a time server is lost for extended timeperiods.

SNTP

SNTP implements a subset of NTP for use in environments with less-stringentsynchronization and accuracy requirements. SNTP uses simple algorithms for time correctionand maintenance and is capable of accuracy to a fraction of a second. To an NTP or SNTPclient, NTP and SNTP servers are indistinguishable.

Time distribution

NTP and SNTP are implemented in a hierarchy of time servers, with public serverssynchronized with reference clocks at the top of the hierarchy and NTP clients at the bottom.Intermediate nodes can be clients and servers. The public time servers distribute time toclients at no cost. Typically, organizations synchronize one or a few local servers to a public


Concepts

server, and then distribute the time within the organization using those local time servers.Figure 1 on page 15 shows a simplified example of a time server distribution hierarchy.

Figure 1. Time server hierachy

There is no need to synchronize with a public time server for time services to work correctlyon VNX. Select NTP servers on page 15 provides more information on choosing the NTPservers.

Select NTP servers

The key to successful time synchronization is the selection of time servers. For someapplications to work correctly, the client and server must have system time approximatelythe same. The best way to do this is to configure VNX and client systems to use the sametime servers. That is, all systems with coordinated time values should determine those valuesbased on a common reference time source. For example, Data Movers should have the sameNTP servers as the domain controllers of a Windows Active Directory environment. For thesame reason, it is ideal to use the same time servers for the Data Movers and Control Stationto provide coordinated time between Control Station and server logs.

Select NTP servers 15

Concepts

If you do not have a dedicated NTP infrastructure for time control, use a Windows Server2003 or Windows 2000 domain controller as a time server for a Data Mover.

Note: By default, all Windows Server 2003 or Windows 2000 domain controllers can operate as timeservers. Furthermore, within a Windows Active Directory environment, all domain controllers operatingas time servers synchronize with the domain controller in the root domain of the forest.

If there is no need for time coordination with clients of a Data Mover, then the ControlStation can be used as a time server for the Data Mover.

CAUTION:Do not use the Control Station as a time server for the Data Movers in the VNX system.Use only standard time servers for all clients and services when possible.

Clock adjustment

A clock offset is calculated after a successful poll of the time server. The clock offset is thedifference between the local time and the time retrieved from the server. The offset can bepositive or negative, which means that the local time is either ahead of or behind the timeserver. Under normal circumstances, SNTP makes time corrections by slewing the systemclock. This means instead of applying the time offset directly, the system time is graduallyincreased or decreased to bring the local time into agreement with the time server. Thisprocess ensures that the time does not change abruptly and the clock never appears to beset behind.

The slew rate on a Data Mover is about 10 percent, which means that it takes approximately1 hour to make a 6-minute correction in system time. Normally, system startup does notslew the clock because the time offset is often too large to adjust in a reasonable amount oftime. However, you can force the Data Mover to slew the time correction on system startup.To correct the system time immediately, force a new time query and immediately set thesystem clock to the returned time, rather than slewing the clock. Alternatively, you can forcea query, but slew the clock to adjust it to the returned time rather than adjusting itimmediately.

Time zones

It is possible to set a time zone on a Data Mover. Each Data Mover keeps its own, separate,universal time (GMT by default). Setting the time zone does not change the Data Movertime. It only changes the way the Data Mover interprets that time when it needs to generatetext-time strings during processing. In other words, the Data Mover generates a time forthe set time zone.

Note: Setting a time zone on a Data Mover is not necessary unless you want an application, such asCheckpoint Virtual File System (CVFS), Virus Checker, or File Transfer Protocol (FTP) to generate atime based upon the local time zone.


Concepts

VNX provides two optional procedures to update the time zone information on the DataMover:

Set a time zone by using the POSIX-method on page 28 provides a procedure to manuallyupdate the time zone information on a Data Mover by using a POSIX string as input.The Control Station contains the time zone database with each time zone represented bya separate file in the directory.

Set a time zone by using the Linux method on page 29 provides a procedure to updatethe time zone information on the Data Mover that uses simple and decipherable strings,corresponding to the time zones available in the Control Station. It also updates thedaylight savings time in the Data Mover for the specified time zone. You might find itmore convenient to set the time zone by using this procedure.

Time services

When starting time services on a Data Mover, up to four NTP servers can be specified, usingthe NTP servers IP addresses. These servers must run the NTP protocol.

Note: The term NTP server is used to refer to either NTP or SNTP servers.

The time services client on the Data Mover polls the specified time servers in the orderspecified. After sending the polling message, the Data Mover waits for a reply. When a replyis received, the time services client corrects the time. If no reply is received, the Data Moverpolls the next time server on the list.

If no time servers are specified, the Data Mover attempts to discover NTP servers on thenetwork, and then automatically configures up to four time servers.

Note: EMC recommends defining specific NTP servers whenever possible.

For the Data Movers in VNX, you can do one of the following:

Start time services immediately by setting the system clock to the returned value.

Start time services, and begin a gradual change of the system clock to the returned valueby slewing the system time.

In either case, use the -interval option to specify the interval between polls of the time server.

Note: You cannot configure time services on a Virtual Data Mover (VDM). A VDMs time servicesconfiguration is based on its associated physical Data Mover.

Start Data Mover time services on page 20 describes the procedure for starting time services.

Time services 17

Concepts


Concepts

3Configuring

The tasks to configure time services are:

Start Data Mover time services on page 20 Verify the time services configuration on page 22


Start Data Mover time services

Starting time services on a Data Mover consists of one of the following tasks:

Start time services Example 1 on page 20

Start time services on a Data Mover and immediately set the system time to the valuereturned by the specified time server.


Start time services on a Data Mover and immediately set the system time to the valuereturned by the specified time server as well as specify the interval between polls of thetime server.


Start time services on a Data Mover and gradually modify the system time to the valuereturned by the specified time server.

Time services on page 17 provides information about starting time services.

Start time services Example 1

Time services are not automatically started on the Data Mover after initialization. However,EMC recommends that you always configure time synchronization between a Data Moverand an external time source.

Action

To start time services on a Data Mover and immediately set the system time to the value returned by the specified timeserver, use this command syntax:

$ server_date timesvc start ntp [[,,...]]

where:

= name of the Data Mover

= IP address of time server

Example:

To start the time service on server_2 and immediately set the system time to the first value returned by the time server,that uses the default interval between polls of the timer server to one hour, type:

$ server_date server_2 timesvc start ntp 192.168.21.250

Output

server_2 : done


Configuring


Action

To start time services on a Data Mover and immediately set the system time to the value returned by the specified timeserver, and to specify the interval between polls of the time server, use this command syntax:

$ server_date timesvc start ntp [-interval [:]][[,,...]]

where:


= hours

= minutes

= IP address of time server

Example:

To start the time service on server_2 and immediately set the system time to the first value returned by the time server,and set the interval between polls of the time server to one hour, 30 minutes, type:

$ server_date server_2 timesvc start ntp -interval 01:30 192.168.21.250

Output

server_2 : done


Action

To start time services on a Data Mover and begin gradually modifying the system time to the value returned by the specifiedtime server, and specifying the interval between polls of the time server, use this command syntax:

$ server_date timesvc start ntp [-sync_delay] [-interval[:]] [[,,...]]

where:


= hours

= minutes

= IP address of NTP server

Example:

To start the time service on server_2 and begin slewing the system time to match the first value returned by the timeserver, and set the interval between polls of the time server to one hour, 30 minutes, type:

Start Data Mover time services 21

Configuring

Action

$ server_date server_2 timesvc start ntp -sync_delay -interval 01:30 192.168.21.250

Output

server_2 : done

Verify the time services configuration

Action

To verify the time services configuration on a Data Mover, use this command syntax:

$ server_date timesvc

where:


Example:

To display the time service configuration for server_2, type:

$ server_date server_2 timesvc

Output

server_2 :

Timeservice State

time: Tue Jul 2 11:02:53 EDT 2004type: sntpsync delay:offinterval: 90hosts: 192.168.21.250

Note

If you did not start time synchronization with an external time source by issuing the server_date timesvcstart ntp command, the output is blank.


Configuring

4Managing

Managing time services on a Data Mover consists of some or all of thefollowing tasks:

Set the Data Mover system time on page 24 Update the Data Mover system time on page 24 Stop Data Mover time services on page 24 Delete a Data Mover time services configuration on page 25 View Data Mover time services statistics on page 25 Set the Data Mover time and date manually on page 26 Display the current time and date for the Data Mover on page 27 Set a time zone by using the POSIX-method on page 28 Set a time zone by using the Linux method on page 29


Set the Data Mover system time

Action

To immediately set the system time on a Data Mover to the value returned by a time server without allowing the normalslewing to occur, use this command syntax:

$ server_date timesvc set ntp

where:


Example:

To poll the time server for the time and set the system time for server_2 to the value returned by the timer server, type:

$ server_date server_2 timesvc set ntp

Output

server_2 : done

Update the Data Mover system time

Action

To force the Data Mover to poll a time server and start a gradual synchronization of the system time on a Data Mover tothe time returned by the time server, use this command syntax:

$ server_date timesvc update ntp

where:


Example:

To poll the timer server and start a gradual synchronization (slewing) of the system time on server_2 to the time returnedby the time server, type:

$ server_date server_2 timesvc update ntp

Output

server_2 : done

Stop Data Mover time services

Action

To stop the time services on a Data Mover, use this command syntax:

$ server_date timesvc stop ntp


Managing

Action

where:


Example:

To stop the timer service on server_2, type:

$ server_date server_2 timesvc stop ntp

Output

server_2 : done

Delete a Data Mover time services configuration

To change a time services configuration, you must delete the existing configuration andthen re-create it.

Action

To delete the time services configuration on a Data Mover, use this command syntax:

$ server_date timesvc delete ntp

where:


Example:

To delete the time services configuration for server_2, type:

$ server_date server_2 timesvc delete ntp

Output

server_2 : done

View Data Mover time services statistics

Action

To view time services statistics on a Data Mover, use this command syntax:

$ server_date timesvc stats ntp

where:


Example:

To display time services statistics for server_2, type:

$ server_date server_2 timesvc stats ntp

Delete a Data Mover time services configuration 25

Managing

Output

server_2 :

Time synchronization statistics since start:hits= 121, misses= 1, first poll hit= 0, miss= 1Last offset: 0 secs, -57639 usecsTime sync hosts:0 1 10.6.8.61

Note

The output includes the list of time servers and the time offset calculated from the most recent poll, -57639 microsecondsor about 58 milliseconds.

The two fields before the IP address under Time sync hosts are the type and the priority fields. The type field determinesif the host in question was configured by an operator or if it was auto-detected (0 = operator configured, 1 = auto-detected).The priority depends on the type. If the host was configured, the priority is 1, otherwise the priority is equal to the timeserver stratem, which indicates how accurate the time server source is (1 means the greatest accuracy while a greaternumber means less accuracy).When a number of hosts is auto-detected, the four fastest hosts are kept at the top. Serversthat respond later can displace only a server with a lower (numerically higher) priority. Therefore, auto-detected serversare ordered by their priority and by how quickly they responded. As configured servers have a priority of 1, they cannotbe displaced by an auto-detected server.

Set the Data Mover time and date manually

Action

To manually set the time and date on a Data Mover instead of configuring time synchronization with an external timesource, use this command syntax:

$ server_date []

where:


[] = year, month, day, hour (in 24-hour system), minutes, and seconds

Example:

To manually set the time and date to 1:36 P.M. on July 16, 2004 for server_2, type:

$ server_date server_2 0407161336

Output

server_2 : done


Managing

Display the current time and date for the Data Mover

Action

To display the current time and date for the Data Mover, use this command syntax:

$ server_date

where:


Example:

To display the time services configuration for server_2, type:

$ server_date server_2

Output

server_2 : Thu Jul 16 13:36:13 EDT 2004

Display the current time and date for the Data Mover 27

Managing

Set a time zone by using the POSIX-method

Time zones on page 16 provides information about setting the time zone by using thePOSIX-method.

Action

To manually set the time zone on a Data Mover, use this command syntax:

$ server_date timezone []

where:


= a POSIX-style time zone specification with the following formats:

(no daylight savings time)

[offset],start[/time],end[/time] (adjusts for daylight savings time)

Note: See the Linux man page for tzset for information about the format.

Examples:

To set the time zone for server_2 when it is unnecessary to adjust for daylight savings time, type:

$ server_date server_2 timezone CST6

To set the time zone to Central Time and adjust for daylight savings time for server_2, type:

$ server_date server_2 timezone CST6CDT5,M4.1.0,M10.5.0

Output

server_2 : done

Verify the time zone

Action

To verify the time zone for server_2, use this command syntax:

$ server_date server_2 timezone

Output

server_2 : Local timezone: CST


Managing

Note

When the time changes to daylight savings time, server_date server_2 timezone returns the daylight time abbreviation.Instead of returning EST or CST, the command returns the time zone as EDT or CDT.

Set a time zone by using the Linux method

Time zones on page 16 provides information about setting a time zone using the Linuxmethod.

Action

To set the time zone on a Data Mover by using the Linux time zone method, use this command syntax:

$ server_date timezone -name

where:


= a Linux style time zone specification

Note: A list of valid Linux time zones is located in the /usr/share/zoneinfo directory.

Example:

To set the time zone to Central Time and adjust the daylight savings time for a Data Mover by using the Linux method,type:

$ server_date server_2 timezone -name America/Chicago

Output

server_2 : done

Set a time zone by using the Linux method 29

Managing


Managing

5Troubleshooting

As part of an effort to continuously improve and enhance the performanceand capabilities of its product lines, EMC periodically releases new versionsof its hardware and software. Therefore, some functions described in thisdocument may not be supported by all versions of the software orhardware currently in use. For the most up-to-date information on productfeatures, refer to your product release notes.

If a product does not function properly or does not function as describedin this document, contact your EMC Customer Support Representative.

ProblemResolution Roadmap for VNX contains additional information aboutusing the EMC Online Support website and resolving problems.


EMC E-Lab Interoperability Navigator on page 32 Diagnose problems on page 32 Error messages on page 33 EMC Training and Professional Services on page 33


EMC E-Lab Interoperability Navigator

The EMC E-Lab Interoperability Navigator is a searchable, web-based application thatprovides access to EMC interoperability support matrices. It is available athttp://Support.EMC.com. After logging in to the EMC Online Support website, locate theapplicable Support by Product page, find Tools, and click E-Lab Interoperability Navigator.

Diagnose problems

To diagnose problems with time services on VNX:

Check that the Data Mover or Control Station has an external IP interface configured.

Type ping , where is the IP address of the time server inquestion, to determine if the Control Station can communicate with the time server.

Use server_ping to determine if the Data Mover can communicate with the time server.Type server_ping , where is the DataMover name and is the IP address of the NTP server.


The statistics command server_date timesvc stats ntp provides outputthat indicates whether the time services received any time updates through NTP. Youcan compare the output of the statistics command before and after performing either theset ntp or update ntp commands to determine if the Data Mover is receiving NTPresponses from any configured NTP server. This does not indicate which servers haveresponded. View Data Mover time services statistics on page 25 provides moreinformation on timesvc stats, Set the Data Mover system time on page 24 provides moreinformation on set ntp, and Update the Data Mover system time on page 24 providesmore information on update ntp.

For UNIX time servers, from Control Station, type rdate -p , where is the name or IP address of the remote time server.

For a Windows time server, type the following command from a Windows client nettime \\, where is the hostname or IP address of the remotetime server.

The command output shows if the NTP or SNTP service is available by displaying thecurrent date and time.

As a last resort, deleting and then re-creating the time services configuration on the DataMover could resolve the problem.


Troubleshooting

Error messages

All event, alert, and status messages provide detailed information and recommended actionsto help you troubleshoot the situation.

To view message details, use any of these methods:

Unisphere software:

Right-click an event, alert, or status message and select to view Event Details, AlertDetails, or Status Details.

CLI:

Type nas_message -info , where is the messageidentification number.

Celerra Error Messages Guide:

Use this guide to locate information about messages that are in the earlier-releasemessage format.

EMC Online Support:

Use the text from the error message's brief description or the message's ID to searchthe Knowledgebase on the EMC Online Support website. After logging in to EMCOnline Support, locate the applicable Support by Product page, and search for theerror message.

EMC Training and Professional Services

EMC Customer Education courses help you learn how EMC storage products work togetherwithin your environment to maximize your entire infrastructure investment. EMC CustomerEducation features online and hands-on training in state-of-the-art labs conveniently locatedthroughout the world. EMC customer training courses are developed and delivered by EMCexperts. Go to the EMC Online Support website at http://Support.EMC.com for course andregistration information.

EMC Professional Services can help you implement your VNX series efficiently. Consultantsevaluate your business, IT processes, and technology, and recommend ways that you canleverage your information for the most benefit. From business plan to implementation, youget the experience and expertise that you need without straining your IT staff or hiring andtraining new personnel. Contact your EMC Customer Support Representative for moreinformation.

Error messages 33

Troubleshooting


Troubleshooting

Appendix A

Windows Domain Controlleras a Time Server

If you do not have a dedicated NTP infrastructure for time control, use aWindows Server 2003 or Windows 2000 domain controller as a time serverfor a Data Mover. By default, all Windows Server 2003 or Windows 2000domain controllers can operate as time servers. Furthermore, within aWindows Active Directory environment, all domain controllers operatingas time servers synchronize with the domain controller in the root domainof the forest.

Note: Only experienced Windows administrators should attempt this procedure.Modifying the Registry can cause serious problems requiring a reinstall of theoperating system. EMC cannot guarantee that problems resulting frommodifications to the Registry can be solved. Use the information provided at yourown risk. Windows online help provides specific information about the WindowsRegistry and its functions.

To use a Windows domain controller as a time server:

Configure a domain controller as a time server on page 36


Configure a domain controller as a time server

1. Log in to the domain controller as the Domain Administrator.

2. From the Start menu in Windows, select Run.

3. Type regedit and click OK.

The Registry Editor dialog box appears.

4. In the Registry Editor, navigate to the following key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W32Time\Parameters\LocalNTP


Windows Domain Controller as a Time Server

5. Right-click Parameters and select Modify. The Edit DWORD Value dialog box appears.

In the Value data, change the value to 1 and click OK.

6. Select Registry Edit to close the Registry Editor and save the change.

Configure a domain controller as a time server 37


7. From the Start menu in Windows, select Programs Administrative Tools Services.The Services dialog box appears.

8. In the Services dialog box, navigate to the W32Time service.

9. Right-click the W32Time service and select Stop.

10. After the service is stopped, right-click it again and click Start.

11. After the service is restarted, close the Services dialog box.



Appendix B

Control Station as a TimeServer

You can use the Control Station as a time server for the Data Movers.

CAUTION: Do not use the Control Station as a time server for the Data Moversin the VNX system. Use standard time servers for all clients and serviceswhenever possible.

To use NTP as the time service on the Control Station, create an NTPconfiguration file and start the NTP daemon.


After time services are configured and started, you can stop, disable, andenable time services as well as verify the time services configuration.

Note: If you are using a standby Control Station, configure the time server settingson the primary and standby Control Station so that they are the same.

Perform the following tasks to manage NTP on the Control Station:

Create an NTP configuration file on page 40 Start Control Station time services on page 40 Stop Control Station time services on page 41 Disable Control Station time services automatic restart on page 41 Enable Control Station time services automatic restart on page 42 Verify a Control Station time services configuration on page 43 Synchronize the Data Mover time services on page 44


Create an NTP configuration file

Use this procedure to create an NTP configuration file on the Control Station.

1. Log in to the Control Station as root by typing:

su -

2. At the prompt, type the root password.

3. Navigate to the following path using a text editor:

/etc/ntp.conf

4. Type the following line in the ntp.conf file:

server minpoll 8

where:

= the address of an NTP time server accessible to the Control Station

Example:

server 172.159.9.10 minpoll 8

5. Comment out the following line, if it exists, by inserting a # at the beginning of the line:

fudge 127.127.1.0 stratum 10

6. Save the file, and then exit.

Start Control Station time services

Use this procedure to start the NTP daemon on the Control Station. After the NTP server isstarted using this procedure, the NTP daemon restarts automatically whenever the ControlStation is restarted.


su -


3. Start the NTP daemon by typing:

# /sbin/service ntpd start

Output:

Starting ntpd: OK

4. Verify that the daemon is running by typing:

# /sbin/service ntpd status


Control Station as a Time Server

Output:

ntpd (pid 1234) is running...

Stop Control Station time services

Use this procedure to stop the NTP server on the Control Station.

CAUTION: If you configured time services on the Data Movers to use the Control Station as theonly time server, you should either stop time services on the Data Movers or configure additionaltime servers on the Data Movers before stopping the time service on the Control Station.


su -


3. Stop the NTP daemon by typing:

# /sbin/service ntpd stop

Output:

Shutting down ntpd: OK

4. Verify that the daemon is stopped by typing:


Output:

ntpd is stopped

Disable Control Station time services automatic restart

After the NTP server is started, the NTP daemon restarts automatically whenever the ControlStation restarts. Use this procedure to disable the NTP server, so that it does not restart ona Control Station restart.


su -


3. Disable the NTP daemon by typing:

# /sbin/chkconfig ntpd off

This prevents the daemon from restarting when the Control Station restarts.

4. Verify that the daemon is disabled by typing:

Stop Control Station time services 41


# /sbin/chkconfig --list ntpd

Output:

ntpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off

The status for each run level (0 through 6) should be off.

Continue with step 5 if you want to immediately stop time services.

5. If needed, immediately stop time services by typing:

# /sbin/service ntpd stop

Output:

Shutting down ntpd: OK

6. Verify that the daemon is stopped by typing:


Output:

ntpd is stopped

Enable Control Station time services automatic restart

If you disable the NTP server on the Control Station, the NTP daemon does not restart whenthe Control Station reboots. Use this procedure to enable the NTP server, so that it doesrestart whenever the Control Station reboots.


su -


3. Enable the NTP daemon by typing:

# /sbin/chkconfig ntpd on

This restarts the NTP daemon whenever the Control Station is restarted.

4. Verify that the daemon is enabled by typing:


Output:

ntpd 0:off 1:off 2:off 3:on 4:off 5:on 6:off

The status for run level 3 should be on.

There might be other run levels also set to on.

If time services are not currently running and you want to immediately start them,continue with step 5.



5. If needed, immediately start time services by typing:

# /sbin/service ntpd start

Output:

Starting ntpd: OK

6. Verify that the daemon is running by typing:


Output:


Verify a Control Station time services configuration

Use this procedure to verify a Control Station time services configuration.

1. Log in to the Control Station.

2. Navigate to the following path using a text editor:

/etc/ntp.conf

3. Look for lines in the ntp.conf file with the following format:

server minpoll 8

where:

= address of an NTP time server accessible to the Control Station

Example:

server 192.168.9.10 minpoll 8

Verify that the server addresses are ones you chose for the time servers.

4. Verify that the daemon is currently running by typing:


Output:


5. Verify that the daemon is enabled and configured to restart when the Control Stationrestarts by typing:


Output:

ntpd 0:off 1:off 2:off 3:on 4:off 5:on 6:off

The status for run level 3 should be on, which means that the daemon restarts when theControl Station restarts. There might be other run levels also set to on.

Verify a Control Station time services configuration 43


Synchronize the Data Mover time services

Action

To synchronize the Data Mover time service using the Control Stations IP address on the internal network as the NTP,use this command syntax:

$ server_date timesvc start ntp [[,,...]]

where:


= IP address of the Control Station

Example:

$ server_date server_2 timesvc start ntp 192.168.1.100 192.168.2.100

Output

server_2 : done



Glossary

C

clock offsetDifference between the local system time and the time retrieved from the time server.

coordinated universal time (UTC)Formerly Greenwich Mean Time (GMT), UTC is the international time standard.

N

Network Time Protocol (NTP)Protocol used to synchronize the realtime clock in a computer with a network time source.

S

Simple Network Time Protocol (SNTP)Adaptation of the Network Time Protocol (NTP) used to synchronize computer clocks in theInternet.

See also NTP.

slewingProcess of gradually correcting the local system time.

T

Transmission Control Protocol (TCP)Connection-oriented transport protocol that provides reliable data delivery.

U

User Datagram Protocol (UDP)Connectionless transport protocol in the TCP/IP stack that allows datagrams to be exchangedwithout acknowledgements or a delivery guarantee.



Glossary

Index

Aautomatic server detection on Data Mover 17

CControl Station

NTP daemondisabling 41enabling 42starting 40stopping 41

ntp.conf file on 40, 43verifying time-services configuration 43

DData Mover

system time, setting from time server 24time and date

setting 26time server

automatic detection 17domain controller as 35limit 17order 17

time serviceverifying configuration 21

time slewing on 16time zone

setting 28, 29using 16

EEMC E-Lab Navigator 32

error messages 33

Mmessages, error 33

NNTP

accuracy of 14ntp.conf file 40, 43ntpd

disable 41enabling 42starting 40stopping 41

overview of 14server limit on Data Mover 17

Sserver_date

settingsystem time 24time and date 26time zone 28, 29

starting time services 20, 44using

set ntp 16update ntp 16

verifying 21slewing

on Data Movers 16overriding on Data Movers 16overview of 16

SNTPaccuracy of 14


SNTP (continued)overview of 14

Ttime service

configuring on domain controller 35disabling on Control Station 41enabling on Control Station 42ordering time servers on Data Mover 17server limit on Data Mover 17setting

system time on Data Mover 24time and date on Data Mover 26time zone on Data Mover 28, 29

starting on Control Station 40stopping on Control Station 41verifying configuration

time service (continued)verifying configuration (continued)

on Control Station 43on Data Mover 21

time service protocoldata format 13public servers 15server hierarchy 15time distribution 15

time servicesstarting 20, 44

time zone 16troubleshooting 31

WWindows domain controller

as time server for Data Movers 35


Index

ContentsPrefaceIntroductionSystem requirementsCautionsUser interface choicesRelated information

ConceptsNTPSNTPTime distributionSelect NTP serversClock adjustmentTime zonesTime services

ConfiguringStart Data Mover time servicesStart time services Example 1Start time services Example 2Start time services Example 3

Verify the time services configuration

ManagingSet the Data Mover system timeUpdate the Data Mover system timeStop Data Mover time servicesDelete a Data Mover time services configurationView Data Mover time services statisticsSet the Data Mover time and date manuallyDisplay the current time and date for the Data MoverSet a time zone by using the POSIX-methodVerify the time zone

Set a time zone by using the Linux method

TroubleshootingEMC E-Lab Interoperability NavigatorDiagnose problemsError messagesEMC Training and Professional Services

Windows Domain Controller as a Time ServerConfigure a domain controller as a time server

Control Station as a Time ServerCreate an NTP configuration fileStart Control Station time servicesStop Control Station time servicesDisable Control Station time services automatic restartEnable Control Station time services automatic restartVerify a Control Station time services configurationSynchronize the Data Mover time services

GlossaryIndex

vnx-timeservices

Documents

emc software

emc powerlink

emc corporationmakes

time services example

emc corporation trademarks

emc vnx seriesrelease

data mover time services

publication date