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®
LifeKeeper for Linux v4.5.0
Sendmail Advanced Message Server (SAMS)
Recovery Kit Administration Guide
Revision B
07/2004
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® The product described in this book is a licensed product of SteelEye Technology, Inc. SteelEye, SteelEye Technology, and LifeKeeper are registered trademarks of SteelEye Technology, Inc. Linux is a registered trademark of Linus Torvalds. Sendmail is a trademark of Sendmail, Inc. Other brand and product names used herein are for identification purposes only and may be trademarks of their respective companies. It is the policy of SteelEye Technology, Inc. to improve products as new techno
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Table of Contents Introduction................................................................................................................................3 Document Contents.............................................................................................................3 LifeKeeper Documentation.................................................................................................4 Reference Documents .................................................................
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SAMS Recovery Kit Administration Guide Introduction The Sendmail Advanced Message Server (SAMS) is a suite of commercial messaging applications. These applications provide various services to clients, such as POP and IMAP, as well as storing and transferring e-mail messages. ® The LifeKeeper for Linux SAMS Recovery Kit provides a mechanism to recover SAMS from a failed primary server onto a backup server in a LifeKeeper environment. Both LifeKeeper and SAMS ensure data integrity throug
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Introduction • LifeKeeper Configuration Tasks. A description of the tasks for creating and managing your SAMS resource hierarchies using the LifeKeeper GUI. • Troubleshooting. This section provides a list of informational and error messages with recommended solutions. LifeKeeper Documentation The following is a list of LifeKeeper related information available from SteelEye Technology, Inc.: • LifeKeeper for Linux Online Product Manual • LifeKeeper for Linux Planning and Installation G
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Requirements Reference Documents The following is a list of reference documents associated with the SAMS product and the LifeKeeper SAMS Recovery Kit: • Sendmail Advanced Message Server Reference Guide • Sendmail Advanced Message Server Installation Guide • Sendmail Advanced Message Server User’s Guide • Sendmail Switch Installation Guide • Sendmail Switch User’s Guide • Sendmail Manual Page • Sendmail, 2nd Edition by Eric Allman & Bryan Costales. (O’Reilly & Associates) • Virtual H
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Requirements • Servers. The Recovery Kit requires two or more supported computers configured in accordance with LifeKeeper requirements described in the LifeKeeper Release Notes, which are shipped with the LifeKeeper product media. • LifeKeeper software. You must install the same version of LifeKeeper software and any patches on each server. Please refer to the LifeKeeper Release Notes for specific LifeKeeper requirements. • LifeKeeper IP Recovery Kit. You must have the same version of t
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Configuring SAMS with LifeKeeper Configuring SAMS with LifeKeeper This section contains information you should consider before you start to configure SAMS and examples of typical LifeKeeper SAMS configurations. Please refer to your LifeKeeper Online Product Manual for instructions on configuring your LifeKeeper Core resource hierarchies. Currently, LifeKeeper only supports an active/standby SAMS configuration (SAMS does not allow multiple instances of itself). Typical LifeKeeper SAMS Env
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Configuring SAMS with LifeKeeper Figure 1 illustrates how SAMS works in a LifeKeeper environment. An active/standby configuration means that only one instance of SAMS can run at one time within the LifeKeeper-protected pair. In an active/standby configuration, one server acts as a primary mailhub or mailserver, while the other server acts as a backup mailhub or mailserver. The primary server runs the LifeKeeper-protected SAMS daemons, accepts client requests, and transports email over t
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Configuring SAMS with LifeKeeper server may fail when a switchover to the backup server occurs. Note that the SAMS Recovery Kit does not require the switchable IP address to have an MX record on the DNS server. Protected Files, Directories and Services The SAMS Recovery Kit protects the following configuration and data directories: • /etc/mail • /etc/md • /var/md/store If not located on a shared file system, the MTA and MSP queue directories (e.g., /var/spool/mqueue, /var/spool/client
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Configuring SAMS with LifeKeeper Sendmail Configuration File The following are a few more important points to note in the Sendmail configuration file (/etc/mail/sendmail.cf). Masquerading Masquerading is used to translate an email address with a given hostname into the address of the domain or that of another mailhub/mailserver. Masquerading can be done at either the domain level or at the host level of the mailhub/mailserver itself. If masquerading has already been established to tran
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Configuring SAMS with LifeKeeper DNS, Sendmail and LifeKeeper DNS offers a mechanism (MX Records) for specifying backup or alternate hosts for mail delivery. This mechanism also allows hosts to assume mail-handling responsibilities for other hosts that are not configured to accept mail, such as a null client. MX records also provide a mechanism of forcing all mail to go to the hub machine or mail server. MX records specify a mail exchanger for a domain name (i.e. a host that will process
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Active/Standby Scenario Active/Standby Scenario The configuration scenario in this section will describe the file movement and the symbolic linking that takes place in a LifeKeeper-protected SAMS environment from the creation of the resource hierarchy, to the extension of that hierarchy to a backup server, to finally what occurs when the backup server takes over after a switchover or failover. Figure 2 Before the SAMS Hierarchy is Created Shared Server 1 Server 2 Storage /etc/m
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Active/Standby Scenario to the switchable IP address when asked for the “Host Name” in the Sendmail Switch installer program. 5. SAMS is tested to ensure that it will work properly on both servers using equivalent configuration options on both servers. 6. The MTA and MSP spool directories (e.g., /var/spool/mqueue and /var/spool/clientmqueue) or theirsubdirectories, if multiple mail queues are being used, must be manually symbolically linked to a directory on a shared file system. This sh
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Active/Standby Scenario The black arrows represent active symbolic links (i.e. the files on Server 1 are actively linked to the shared storage device after the resource is created). Configuration Notes During the creation of the SAMS resource instance on the primary server (i.e. Server 1), the Recovery Kit moves the /etc/md, /etc/mail, and /var/md/store to the shared file system. It then creates a symbolic link on the local server (Server 1) to the file on the shared device. IMPORTANT:
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Active/Standby Scenario The gray arrows represent dangling links (i.e. the files on Server 2 are linked to the shared storage device, but the shared device is not mounted on Server 2. Therefore, the links on Server 2 are not active). Configuration Notes During the extension of the SAMS resource instance to the backup server (i.e. Server 2), the Recovery Kit symbolically links the SAMS configuration and data directories /etc/md, /etc/mail, and /var/md/store to the versions on the shared f
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Active/Standby Scenario The gray arrows represent dangling links (i.e. the files on Server 1 are linked to the shared storage device, but the shared device is not mounted on Server 1. Therefore, the links on Server 1 are not active). Configuration Notes When Server 2 becomes the active or primary server, the following occurs: 1. LifeKeeper unmounts the shared file system from Server 1 and mounts it on Server 2. The dangling links on Server 2 now point to actual files. 2. Server 1 now con
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LifeKeeper Configuration Tasks LifeKeeper Configuration Tasks You can perform the following configuration tasks from the LifeKeeper GUI. The following four tasks are described in this guide, as they are unique to a SAMS resource instance, and different for each Recovery Kit. • Create a Resource Hierarchy. Creates an application resource hierarchy in your LifeKeeper cluster. • Delete a Resource Hierarchy. Deletes a resource hierarchy from all servers in your LifeKeeper cluster. • Extend
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LifeKeeper Configuration Tasks same drop down menu choices as the Edit menu. This, of course, is only an option when a hierarchy already exists. You can also right click on a resource instance in the Resource Hierarchy Table (right-hand pane) of the status display window to perform all the configuration tasks, except Creating a Resource Hierarchy, depending on the state of the server and the particular resource. Creating a SAMS Resource Hierarchy IMPORTANT: Before you create your SAMS
