1 INUVIKA TECHNICAL GUIDE FILE SERVER HIGH AVAILABILITY OVD Enterprise External Document Version 1.0 Published Passing on or copying of this document, use and communication of its content not permitted without Inuvika written approval
2 PREFACE This document describes the architecture that can be employed to implement a high availability solution for the OVD File Server together with an example implementation. Page 2
3 HISTORY Version Date Author Comments mm-dd-yy Sarina Dhaliwal Initial Document Page 3
4 TABLE OF CONTENTS 1. INTRODUCTION What is High Availability? Single Points of Failure Resiliency Solution Overview Terminology Configurations Pre-Requisites General Minimum Requirements Recommended Requirements HIGH AVAILABILITY FOR OVD FILE SERVERS External Components Data Replication Virtual IP Session Manager Role OVD Sample Configurations Load Balancer without External SAN or NAS Using External NAS or SAN and Load Balancer GLUSTERFS AND CTDB IMPLEMENTATION Overview Requirements Basic System Configuration Scripted Implementation Session Manager Configuration Troubleshooting GlusterFS CTDB TESTING FILE SERVER HIGH AVAILABILITY General Test Scenarios Test Test Test Test Page 4
5 4.2.5 Test UPGRADE OVD AND ENABLE HIGH AVAILABILTIY Upgrade to OVD Version Migrate Load Balancing Setup to A High Availability Cluster GENERAL TROUBLESHOOTING OVD File Server General Information Service Logs OSM/OAC Other Firewall EXTENDING THE DESIGN External Data Storage Page 5
6 CONVENTIONS The table below shows the typing conventions used in this document. These conventions denote a special type of information. Typing convention Information type Bold-face text Italics Double Quotes Dialog Fields Commands Buttons File names Document titles Document references Menu Options Page 6
7 1. INTRODUCTION This document describes the architecture that can be employed to implement a high availability solution for the OVD File Server (OFS). Such an implementation will allow continued access to OVD user profiles and shared folders should one of the OVD File Servers fail. The document contains the details of a sample implementation for an Ubuntu OVD server farm using two open source tools (GlusterFS and CTDB). 1.1 WHAT IS HIGH AVAILABILITY? High availability refers to a system s ability to continue normal operation in the event of a system or component failure. A highly available system is one that uses groups or clusters of computers/components monitored by high availability software so if a critical component fails, normal operations are restarted on the backup components in a process known as failover. When the primary system is restored, normal operation can be shifted back in a process known as failback. The main purpose of a high availability system is to minimize system downtime and data loss SINGLE POINTS OF FAILURE In order to be considered highly available, a system should minimize the number of single points of failure (SPOFs). A SPOF is a critical system component that will cause system failure or data loss if it goes down. In order to eliminate SPOFs, you must add redundancy and replication. Redundancy involves providing backup components that the system can switch over to if a critical component fails and replication involves ensuring the backup system has access to the same data as the primary system RESILIENCY Highly available systems should strive for resiliency. This means system failures should be handled quickly and effectively and failover events (switching to backup/primary systems or components) should be as seamless and as quick as possible so as to minimize the impact on users. Resiliency will allow you to guarantee a minimum uptime for your system. 1.2 SOLUTION OVERVIEW The OVD File Server is a component that is used to store user profiles and session data, as well as shared folder data among users that log in to OVD. It is a server which is used by the session manager and facilitates persisting of program preferences, caches, any user-specific saved data, Page 7
8 or data created by the user. It stores it in a secure manner and is only accessible by that user the next time they log into OVD. The OFS has the ability to share folders across user groups, which allows multiple users to see and manage the same data for collaboration. This means that the OFS is a critical component of an OVD farm. Any failures involving it will result in user data being unavailable, leaving affected users unable to login and start sessions. OVD File Server High Availability aims to make the OFS highly available so in case of failures, the data is still accessible and service is not interrupted TERMINOLOGY For the duration of this document, a cluster will refer to a collection of hardware components that work together to provide high availability and node will refer to each individual component in the cluster. For OVD File Server High Availability (OVD FS HA), each OFS is considered a node and the collection of them is a file server cluster CONFIGURATIONS ACTIVE/PASSIVE HA CONFIGURATION In an active/passive high availability configuration, redundancy is used to ensure high availability. A redundant instance of a resource is maintained which remains idle, listening to the primary system. If a failure occurs in the primary node, the idle node activates. The process of failover occurs, relocating resources and connections from the failed primary node to the backup node. For this configuration, backup instances have identical state through a data replication and synchronization process (see section 2.1 External Components) so a request to one instance is the same as to another, meaning a switch to a backup system will still give end users access to the same data. This configuration can also be setup to failback, either automatically or manually. For automatic failback, once the failed node is back online, resources and connection are moved back to it, reinstating it as the primary node and the secondary node returns to idle, listening mode. For manual, the administrator can switch service back to the primary node or let the secondary node function as the new primary node and use the old primary node as the new backup. Page 8
9 ACTIVE/ACTIVE HA CONFIGURATION In an active/active high availability configuration, redundancy is still used to ensure high availability, as in each service has a backup that the system can revert to in case of failure, but in this setup all systems are online and working concurrently. In the case of a failure, when failover occurs it is relocating resources and connections to a system that is already working. So instead of activating and taking this load on, the backup system already has its own load and simply takes on more. In this case it is not true failover but rather resource reallocation/load balancing. For this configuration, all instances have identical state through a data replication and synchronization process (see section 2.1 External Components) so a request to one instance is the same as to another, meaning each running instance can take on another s load with no difference in service to the end user. This configuration can also be setup to failback automatically. Since an active/active configuration has all instances operating at once, a load balancer is typically used to allocate resources across all instances. Once the failed node is back online, the load balancer will redistribute resources and connections between all instances, included the newly repaired one. 1.3 PRE-REQUISITES GENERAL OVD File Server High Availability is an enterprise feature, so you must be using OVD Enterprise, version 1.3 or higher. This feature is not a standalone OVD capability and requires: Investigation of the existing IT setup in order to determine which existing components can be used and which components will need to be installed Implementation of a data replication mechanism (follow the guidelines in section 2.1 External Components) Implementation of a Virtual IP (VIP) mechanism (follow the guidelines in section 2.1 External Components) o The VIP is an IPv4 IP that is dedicated and allocated to be used by the OVD FS HA mechanism to determine the OFS node's availability. This IP must not already be used in your LAN network and should be a static assigned IP and in the same subnet as the two File Servers. Page 9
10 1.3.2 MINIMUM REQUIREMENTS 2 dedicated OVD File Servers (OFS). For High Availability the file server must not act as an OVD Application Server, Session Manager, or any other such service. It should be setup with the only the File Server role. An understanding of network and system administration RECOMMENDED REQUIREMENTS An external load balancer to manage the VIP, such as F5 An external NAS to store the data All OVD FS servers should run the same Linux distribution and have the same version and system architecture 2 NICs / vlan o One dedicated VLAN (and NIC if possible / recommended) for Heartbeat/Gluster (data replication and synchronization) management Redundant power supplies which power your external storage device(s) and the servers. Page 10
11 2. HIGH AVAILABILITY FOR OVD FILE SERVERS Inuvika OVD provide two types of storage: User Profile (includes session data) Shared Folder The OVD File Server (OFS) component provides centralized access to user data for both Linux and Windows Application Servers. For instance, a user who is running a session with both Linux and Windows can first create a file with a Linux application, and can then open the same file with a Windows application without requiring any permission or dealing with any cache issues. The goal of having a highly available setup for your OVD Farm is to allow for servers of the same role to carry out the tasks when another server of the same role goes down with minimized or no negative consequences from it being down. A highly available OFS setup provides: Availability of your data Availability of data access (CIFS & WebDAV) In other words, if one of your File Servers crashes: No data will be lost Running sessions will remain alive after failover (potentially up to 1 minute I/O freeze) New sessions can still be started after the failover has completed (delay of less than 1 minute) 2.1 EXTERNAL COMPONENTS OVD File Server High Availability is not a standalone OVD feature. The following external components are required in order to setup a highly available OFS DATA REPLICATION In order to ensure users still have access to their OVD data (Shared Folders and User Profiles) when failover occurs, the secondary system must have the same available data as the primary system. This can be achieved through replication, a process by which data is synchronized between the primary and secondary systems Additional benefits of this synchronization are: No data is lost if a crash occurs The Samba configuration will be replicated between the OFS servers Page 11
12 Figure 1: Data replication between two OVD File Servers All the OVD File Servers in your highly available cluster must have synchronized data on the /var/lib/ovd/slaveserver/fs.real folder or, if no default location is specified, the data_dir path defined in the /etc/ovd/slaveserver/slaveserver.conf file. The data replication / synchronization mechanism can be one of the following: An external NAS (CIFS, NFS) GlusterFS XtreemFS Inotify + SSH + Rsync / Unisson The Administrator must choose an option to implement from this list. If your system already has a suitable NAS, we strongly recommend you use it. Otherwise, section 3 will guide you on how to setup a GlusterFS volume. For the remainder of this document all examples will be using GlusterFS for the data replication component VIRTUAL IP Virtual IP addresses (VIPs) are a core component of high availability. A VIP is an IP address mapping. It is used in place of an actual IP address so that the same VIP can be used to point to Page 12
13 many different IPs. For a high availability cluster, VIPs are used to access critical components so that if they fail, the load balancer can change the mapping to have the VIP point to a secondary component. This design is used in a standard active/passive (see section 2.3) setup. The active node is accessed using the VIP. In the case of a failover, the passive node is promoted and the VIP is shifted to point to it instead. Applications using the primary node have their connections broken and reconnected, with the VIP now pointing to the new setup. For a highly available OVD Farm, the VIP will be used for all CIFS/WebDAV connections to the OFS. This VIP must always target an online node. In the diagram below, the VIP directs traffic to OVD FS 1 until failure occurs. When it does, it shifts traffic to OVD FS 2 instead, until OVD FS 1 is restored. Figure 2: Two OVD File Servers in a highly available cluster. The VIP management solution can be one of the following: An external Load Balancer such as F5 Pacemaker + Heartbeat / Corosync Samba CTDB Page 13
14 The Administrator must choose an option to implement from this list. If your system already has a suitable Load Balancer, we strongly recommend you use it. Otherwise, section 3 will guide you on how to setup Samba CTDB. For the remainder of this document all examples will be using CTDB for the VIP management component. 2.2 SESSION MANAGER ROLE The OVD Session Manager (OSM) currently provides support for one High Availability File Server cluster. The OSM is aware of each File Server in the cluster and acts as the user management component, system management component, and primary configuration for the entire OVD system. You can configure the OSM through the OVD Administration Console (OAC) to implement high availability for the file servers (see section 3.5 Session Manager Configuration). 2.3 OVD SAMPLE CONFIGURATIONS Depending on the data replication and virtual IP solution, the following configurations are supported for File Server High Availability. Note: Inuvika strongly recommends that you setup the VIP as a failover solution i.e. Active/Passive. Page 14
15 2.3.1 LOAD BALANCER WITHOUT EXTERNAL SAN OR NAS Figure 3: Load Balancer without External SAN or NAS Page 15
16 2.3.2 USING EXTERNAL NAS OR SAN AND LOAD BALANCER Figure 4: External NAS or SAN and Load Balancer Page 16
17 3. GLUSTERFS AND CTDB IMPLEMENTATION This section will walk you through the set-up and configuration of GlusterFS and CTDB (Clustered Trivial Data Base) to provide highly available file storage. 3.1 OVERVIEW High availability in OVD required two external components: data replication and VIPs. In this section, we will use two open source tools for these components: GlusterFS for data replication and CTDB for VIP management. GlusterFS is a clustered file system that can provide network storage that can be made redundant, fault-tolerant, and scalable. It can be used to provide high availability of storage by replicating it between servers. Visit their official website to learn more. CTDB is a thin and efficient database that allows for the creation of a clusterized Samba. It makes it possible for Samba to serve data simultaneously from different hosts in a network and provides high availability features such as node monitoring (for the purposes of failover and failback), node failover, and IP takeover (reassign VIP addresses during failover and failback). Visit their official website to learn more. Figure 5: A highly available OVD File Server setup using GlusterFS and CTDB. Note this implementation does not use a hardware load balancer. The VIP is a software bound interface. Page 17
18 3.2 REQUIREMENTS Two OVD File Servers that both: o Run the same Linux distribution, version, and have the same system architecture. o Have a dedicated data partition mounted in /mnt/data. We recommend this partition be hosted by a RAID 5. Two NICs/VLAN o One dedicated VLAN (and NIC if possible) for CTDB and Gluster management. OVD File Server (OFS) role is running on the server and no other roles are active on that server (it s not possible to mix several roles in this configuration). Download the OVD File Server High Availability package, ovd-fs-ha-helper_<version>.zip from the Inuvika archives (version 1.3 and higher), in the packages folder. Extract the following files onto each OFS node before you begin installation: o glusterfs-server.init.sh o glusterfs-client.init.sh o ctdb.init.patch o ovd-fs-ha-setup-node Change the permissions for the three files from the point above to ensure they are executable (use the command: chmod +x).! This example setup assumes you file servers are using Ubuntu If you are using a different Linux distribution, you can study the scripts used in this example as a base to understand the necessary commands and modify them to work for the distribution you are using. 3.3 BASIC SYSTEM CONFIGURATION Network configuration NOTE: the Ubuntu script that will be used in section 3.4 will have an interactive guide that prompts for and then checks the appropriateness of your IP choices and whether they match the current LAN and subnet mask. But for the sake of providing a concrete example, the following IPs are examples and assume a class C network of /24 with the /24 subnet of o Dedicated VLAN: /24 node1: node2: o LAN: /24 node1: node2: VIP: (NOTE: be sure this IP is not in the DHCP range if a DHCP server is running on the LAN) Page 18
19 Hostname resolution o On node1, modify the /etc/hostname to have the name node1 and /etc/hosts files to resolve the node2 FQDN address on the dedicated LAN. Similarly, on node2, the hostname is node2 and hosts file contains an entry for node1 on the dedicated LAN. For example on node 1, the /etc/hosts file entry should be: node node2 And for example on node 2, the /etc/hosts file entry should be: node node1 3.4 SCRIPTED IMPLEMENTATION Run the ovd-fs-ha-setup-node script from the OVD File Server High Availability package (see section 3.2 Requirements) on each File Server. This script will install and configure GlusterFS, CTDB, and the OFS. If you would like to see how the system is setup exactly, you can read the script for all the steps. You may also modify it for custom installations (e.g. using different open source tools for data replication and VIP management). This script can be run automatically or in an interactive mode. For our GlusterFS + CTDB example, run it in automatic mode on each OFS with the following commands (change the IPs to your own): On node1, run: NODE_ID=1 NODE2_IP= VIP= bash ovd-fs-hasetup-node On node2, run: NODE_ID=2 NODE1_IP= bash ovd-fs-ha-setup-node Page 19
20 If you are going to run the script in interactive mode instead, use the command:./ovd-fs-ha-setup-node And provide any information the script prompts you for.! If you are going to run the script in interactive mode, make sure you know the IP addresses of both OFS nodes before beginning as you will be prompted for them during the installation process. 3.5 SESSION MANAGER CONFIGURATION Once the ovd-fs-ha-setup-node script completes, the system is ready and you must now configure the OVD Session Manager (OSM). Login to the OVD Administration Console (OAC), go to the Servers tab and select File Server Clusters. Here you can create your new cluster, Give it a name and click Add. You will be redirected to the management page for your new cluster, where you can define the different components. Here you should add the OVD File Servers that are part of your cluster and set the IP of your VIP. In order to have File Server High Availability, a File Server Cluster requires at least two OVD File Servers and both should be online and in production mode. If either OFS is offline or in maintenance mode, the one that is still available will be used but the system will not have high availability. NOTE: If you set any of your file servers to maintenance mode, the servers will still remain synchronized as the data synchronization is handled by GlusterFS + CTDB, which will still be functional on the servers in maintenance mode. When your cluster is fully defined, uncheck the Maintenance option and save to switch the cluster to production. Page 20
21 Figure 6: Cluster management page in the OAC.! The OVD FS HA feature does not actively alert the administrator of a failback or a fault in the high availability. It is up to the administrator to put in hardware or their own detection system to ensure that the services and the hardware are running and working. However, OVD will still log the event of a failback or resiliency FS switchover, so an administrator can regularly monitor logs for these notifications. Page 21
22 3.6 TROUBLESHOOTING GLUSTERFS For general GlusterFS troubleshooting, please refer to the GlusterFS documentation. If your issue is not addressed on this page, follow these suggestions to investigate and identify any issues: GENERAL STATUS INFORMATION: Check the peer status in GlusterFS using the command: gluster peer status If nothing looks amiss, you can then check the GlusterFS volume status and info using the command: gluster volume info all CLIENT-SIDE MOUNT POINT Confirm that GlusterFS directories have been mounted successfully using the command: mount grep gluster The resulting output should show that the directories were successfully mounted on /mnt/gluster-volume1. You can navigate to this directory and list the contents to verify that it has been mounted VERIFY DATA REPLICATION If the check above verified the directories were successfully mounted on /mnt/glustervolume1, you can check that the data replication and synchronization is working as expected. Check the /mnt/gluster-volume1/ovd folder on each OFS node. Both folders should contain identical data. If there are any differences, the data replication and synchronization processes are not functioning or not functioning correctly. Page 22
23 SERVICE STATUS Check the GlusterFS service status using the command: service glusterfs-server status SERVICE LOGS Look through the GlusterFS service logs to see if any unexpected behavior has been logged. The logs will be located in /var/log/glusterfs GLUSTERFS PROCESSES Check which, if any, GlusterFS processes are currently running on your system using the command: ps auxf grep gluster DATA VOLUME PATH Ensure that the data volume path is correct. It should be /mnt/data/gluster/vol1. Navigate to it and check that the contents are correct CTDB For general CTDB troubleshooting, please refer to the CTDB documentation. If your issue is not addressed on this page, follow these suggestions to investigate and identify any issues: GENERAL STATUS INFORMATION Check the status of CTDB to see if there is any anomalous behavior. Check basic information and the status of your cluster nodes using the command: ctdb status The output will inform you of the status of each node (if they are okay or not) and the status of your system (Recovery mode should be NORMAL if the system is okay). Check the status of the IP addresses using the command: ctdb ip Each IP that is being served will be listed along with the cluster node serving it. Page 23
24 SERVICE STATUS Check the statuses of services used by CTDB and ensure they are all running. Check CTDB using the command: service ctdb status Check Samba using the command: service smbd status Check the NetBIOS name server using the command: service nmbd status All three of these services should be running in order for CTDB to be functioning properly SERVICE LOGS Look through the CTDB service log to see if any unexpected behavior has been logged. The logs will be located at /var/log/ctdb/log.ctdb. Page 24
25 4. TESTING FILE SERVER HIGH AVAILABILITY The reason to create a highly available OFS system is so there is little to no impact on the environment if one server crashed. So it s important to simulate a server crash and ensure the feature is working as intended. Once your highly available system is setup, you can carry out some of the tests in this section to validate that the system is working correctly. 4.1 GENERAL Scenario 1: Network Down You can shut down the network your master virtual machine is running on and then check the system s behavior. Some suggestions for what to look for are below. Scenario 2: Power Down You can shut down the master virtual machine and then check the system s behavior. Some suggestions for what to look for are below. System Checks: Are running sessions impacted? o In a highly available setup, there will be up to a 1 minute I/O freeze for running sessions. Any other impact is not expected. Did the VIPs switch between servers? o If a server goes down, the VIP should shift to one of the backups. What happens when the network is enabled again? o Does the system automatically failback to the primary nodes if it has been setup to do that? The only situation in which it won t is if you are using an active/active configuration with a manual failback switch. 4.2 TEST SCENARIOS For more thorough testing, you can follow the test matrices described in this section. Each test details a scenario ( State ) and the status of each OFS. Carry out the scenarios with the File Servers in the specified state. If you get the results listed in the test matrix, the test passed and you can proceed. If your results differ from the ones listed, there may be a problem with your system setup. Page 25
26 4.2.1 TEST TEST TEST TEST TEST 5 Page 26
27 5. UPGRADE OVD AND ENABLE HIGH AVAILABILTIY This section will guide you in upgrading to a newer version of OVD without any data loss and converting from load balancing, if applicable, to a highly available file server setup. 5.1 UPGRADE TO OVD VERSION 1.3 In order to use OVD File Server High Availability, you will need to upgrade OVD to version 1.3 or higher. The OVD software repository is available at You can do this without any data loss by following these steps: 1. Switch all servers to maintenance mode (you can do this from the Servers page in the OAC). 2. Switch the OSM to maintenance mode (you can do this from the main page of the OAC). 3. Upgrade the OSM and Application Servers (ApS) by following the release notes that are available on the found on the OVD software repository. 4. Upgrade all File Servers by following the relevant instructions in the release notes. 5. After you are done upgrading, switch all servers back to production mode. 6. Switch the OSM to production mode. 5.2 MIGRATE LOAD BALANCING SETUP TO A HIGH AVAILABILITY CLUSTER If you have multiple file servers and have been using the load balancing feature, you may continue to use the load balancing configuration or you can update the environment to use high availability instead. You can do this by following these steps: 1) Stop the OVD service if it s already installed and running service ovd-slaveserver stop 2) Follow section 3 to setup a highly available system using GlusterFS and CTDB. Or modify the script provided in section 3 to use any other tools you may prefer. Page 27
28 NOTE: The script provided in section 3 will ensure no data is lost. It does this by executing the following command: rsync -avp /var/lib/ovd/slaveserver/fs.real/./ /mnt/glustervolume1/ovd/./ By executing that command on each existing OFS in the OVD farm, the script will migrate the data from each server to the cluster, ensuring each server will have all data.! If you are implementing your setup in a different way and not using the script provided in section 3, you must execute the rsync command manually to migrate the existing data to the new folder within your high availability setup. Page 28
29 6. GENERAL TROUBLESHOOTING When encountering problems with your highly available setup, the path for investigation should be Data Replication (ex: GlusterFS) > VIP Management (ex: CTDB) > OFS > OSM/OAC. If you are using GlusterFS or CTDB, see section 3.6 for troubleshooting tips. If you are using any other tools for data replication and/or VIP management, please look at the official documentation for the tool. If there are no issues at the data replication or VIP management levels, read on for troubleshooting tips for the OFS and OSM/OAC. 6.1 OVD FILE SERVER GENERAL INFORMATION Check which, if any, OFS processes are currently running on your system using the command: ps auxf grep ovd-slaveserver SERVICE LOGS Look through the OFS service logs to see if any unexpected behavior has been logged. The logs will be located at /var/log/ovd/slaveserver.log and /var/log/ovd/rufs.log. Check slaveserver.log first as it will contain most pertinent information rufs.log can be checked if additional details are required (NOTE: this log file contains many debugging messages and may be too difficult to parse enough meaningful information from - use it as a last resort). 6.2 OSM/OAC Check the general status of the cluster through the OAC. Login to the OAC, go to the Servers tab and select File Server Clusters. Check that the cluster is defined. If it is, there should be an entry for it on this page. Click on the cluster to go to its management page. Here you should check if: The cluster is in production mode The VIP is valid All nodes are online and in production mode Page 29
30 If everything is fine, you can check the OSM logs for any anomalous behavior. Go to the Status tab and select Logs. 6.3 OTHER FIREWALL Check your firewall to make sure it is not interfering with the cluster. Monitor the traffic and ensure CIFS/WebDAV communication is targeting the appropriate VIP and that the OSM is also able to communicate with the VIP. Page 30
31 7. EXTENDING THE DESIGN 7.1 EXTERNAL DATA STORAGE OVD File Server High Availability ensures the servers are highly available, as well as the files on each separate file system. There is an alternative to this setup though you can use a separate NFS server to serve the files instead of using GlusterFS and separating them between the servers. The script provided in section 3 will not cover this hardware file server high availability, so the research and implementation of that is for the reader to investigate. Figure 7: OVD File Server High Availability using an external NAS. The mount point in the figure is from the example setup in section 3. It would now point to your external storage instead. The advantages of making the file mount point highly available using a hardware RAID device are: - Speed: persisting data on the file server itself may be slower than an NFS server which has built-in RAID - Reducing the file server disk space requirements: offloading the profiles and session data onto an NFS server which is equipped for bigger files is more efficient. Having them on the file server itself is duplication and may (unnecessarily) dramatically increase the size of the partitions - Convention: it is normal convention to have one centralized external mount point for a file share instead of duplicating the synchronization. Page 31
High Availability Solutions for the MariaDB and MySQL Database 1 Introduction This paper introduces recommendations and some of the solutions used to create an availability or high availability environment
Clustering ExtremeZ-IP 4.1 Installing and Configuring ExtremeZ-IP 4.x on a Cluster Version: 1.3 Date: 10/11/05 Product Version: 4.1 Introduction This document provides instructions and background information
Configuring Windows Server Clusters In Enterprise network, group of servers are often used to provide a common set of services. For example, Different physical computers can be used to answer request directed
Licensing: Setting Up the License Server on a Microsoft Cluster By the Citrix Publications Department Citrix Systems, Inc. Notice The information in this publication is subject to change without notice.
Getting Started with Hyper-V and the Scale Computing Cluster Scale Computing 5225 Exploration Drive Indianapolis, IN, 46241 Contents Contents CHAPTER 1 Introduction to Hyper-V: BEFORE YOU START. vii Revision
Administrator Guide VMware vcenter Server Heartbeat 6.3 Update 1 This document supports the version of each product listed and supports all subsequent versions until the document is replaced by a new edition.
Active-Active and High Availability Advanced Design and Setup Guide Perceptive Content Version: 7.0.x Written by: Product Knowledge, R&D Date: July 2015 2015 Perceptive Software. All rights reserved. Lexmark
EMC Data Domain Management Center Version 1.1 Initial Configuration Guide 302-000-071 REV 04 Copyright 2012-2015 EMC Corporation. All rights reserved. Published in USA. Published June, 2015 EMC believes
vcenter Server Heartbeat 5.5 Update 2 This document supports the version of each product listed and supports all subsequent versions until the document is replaced by a new edition. To check for more recent
FactoryTalk View Site Edition V5.0 (CPR9) Server Redundancy Guidelines This page left intentionally blank. FTView SE 5.0 (CPR9) Server Redundancy Guidelines.doc 8/19/2008 Page 2 of 27 Table of Contents
RSA Authentication Manager 7.1 to 8.1 Migration Guide: Upgrading RSA SecurID Appliance 3.0 On Existing Hardware Contact Information Go to the RSA corporate website for regional Customer Support telephone
FioranoMQ 9 High Availability Guide Copyright (c) 1999-2008, Fiorano Software Technologies Pvt. Ltd., Copyright (c) 2008-2009, Fiorano Software Pty. Ltd. All rights reserved. This software is the confidential
Installing and Using the vnios Trial The vnios Trial is a software package designed for efficient evaluation of the Infoblox vnios appliance platform. Providing the complete suite of DNS, DHCP and IPAM
istorage Server: High-Availability iscsi SAN for Windows Server 2008 & Hyper-V Clustering Tuesday, Feb 21 st, 2012 KernSafe Technologies, Inc. www.kernsafe.com Copyright KernSafe Technologies 2006-2012.
Metalogix SharePoint Backup Publication Date: August 24, 2015 All Rights Reserved. This software is protected by copyright law and international treaties. Unauthorized reproduction or distribution of this
Installation Guide for Microsoft Hyper-V Egnyte Inc. 1890 N. Shoreline Blvd. Mountain View, CA 94043, USA Phone: 877-7EGNYTE (877-734-6983) www.egnyte.com 2013 by Egnyte Inc. All rights reserved. Revised
Cluster to Cluster Failover Using Double-Take Cluster to Cluster Failover Using Double-Take Revision 2.2.0 published March 2004 Double-Take, GeoCluster and NSI are registered trademarks of NSI Software,
Network Load Balancing Step by Step installation of Network Load Balancing in Windows Server 2008 R2. Prerequisite for NLB Cluster 1. Log on to NODE1 Windows Server 2008 R2 system with a domain account
Remote Application Server Version 14 Last updated: 06-02-15 Information in this document is subject to change without notice. Companies, names, and data used in examples herein are fictitious unless otherwise
Synology High Availability (SHA) Based on DSM 4.3 Synology Inc. Synology_SHAWP_ 20130910 Table of Contents Chapter 1: Introduction Chapter 2: High-Availability Clustering 2.1 Synology High-Availability
Virtual Appliance Setup Guide 2015 Bomgar Corporation. All rights reserved worldwide. BOMGAR and the BOMGAR logo are trademarks of Bomgar Corporation; other trademarks shown are the property of their respective
24_0672329565_ch18.qxd 9/7/07 8:37 AM Page 647 CHAPTER 18 Administering and Managing Failover Clustering Failover clustering is one of four SQL Server 2005 highavailability alternatives. Other SQL Server
Red Hat Cluster Suite HP User Society / DECUS 17. Mai 2006 Joachim Schröder Red Hat GmbH Two Key Industry Trends Clustering (scale-out) is happening 20% of all servers shipped will be clustered by 2006.
Remote Application Server Version 14 Last updated: 25-02-15 Information in this document is subject to change without notice. Companies, names, and data used in examples herein are fictitious unless otherwise
Connect With Confidence Astaro Deployment Guide Clustering and Hot Standby Table of Contents Introduction... 2 Active/Passive HA (Hot Standby)... 2 Active/Active HA (Cluster)... 2 Astaro s HA Act as One...
High Availability and Clustering AdvOSS-HA is a software application that enables High Availability and Clustering; a critical requirement for any carrier grade solution. It implements multiple redundancy
QNAP in vsphere Environment HOW TO USE QNAP NAS AS A VMWARE DATASTORE VIA NFS Copyright 2009. QNAP Systems, Inc. All Rights Reserved. V1.8 How to use QNAP NAS as a VMware Datastore via NFS QNAP provides
Introduction As you may already know, GlusterFS provides several methods for storage access from clients. However, only the native FUSE GlusterFS client has built-in failover and high availability features.
StarWind iscsi SAN Software: Using StarWind with MS Cluster on Windows Server 2003 www.starwindsoftware.com Copyright 2008-2011. All rights reserved. COPYRIGHT Copyright 2008-2011. All rights reserved.
Configuring a Microsoft Windows Server 2012/R2 Failover Cluster with Storage Center Dell Compellent Solution Guide Kris Piepho, Microsoft Product Specialist October, 2013 Revisions Date Description 1/4/2013
HP StoreVirtual DSM for Microsoft MPIO Deployment Guide HP Part Number: AX696-96254 Published: March 2013 Edition: 3 Copyright 2011, 2013 Hewlett-Packard Development Company, L.P. 1 Using MPIO Description
Getting Started Guide Microsoft Corporation Published: December 2005 Table of Contents Getting Started Guide...1 Table of Contents...2 Get Started with Windows Server 2003 R2...4 Windows Storage Server
This document shows you how to use Drobo iscsi SAN storage with Double-Take Availability to deliver replication and DR for servers and applications. Double-Take Availability from Vision Solutions performs
TECHNICAL WHITE PAPER: DATA AND SYSTEM PROTECTION Achieving High Availability with Symantec Enterprise Vault Chris Dooley January 3, 2007 Technical White Paper: Data and System Protection Achieving High
Installing and Configuring a SQL Server 2014 Multi-Subnet Cluster on Windows Server 2012 R2 Edwin Sarmiento, Microsoft SQL Server MVP, Microsoft Certified Master Contents Introduction... 3 Assumptions...
Pharos Uniprint 8.4 Maintenance Guide Document Version: UP84-Maintenance-1.0 Distribution Date: July 2013 Pharos Systems International Suite 310, 80 Linden Oaks Rochester, New York 14625 Phone: 1-585-939-7000
High Availability & Disaster Recovery Development Project Concepts, Design and Implementation High Availability & Disaster Recovery Development Project CONCEPTS Who: Schmooze Com Inc, maintainers, core
Polarion Software CONCEPT High Availability of the Polarion Server Installing Polarion in a high availability environment Europe, Middle-East, Africa: Polarion Software GmbH Hedelfinger Straße 60 70327
Quick Start Guide Cerberus FTP is distributed in Canada through C&C Software. Visit us today at www.ccsoftware.ca! How to Setup a File Server with Cerberus FTP Server FTP and SSH SFTP are application protocols
Configure AlwaysOn Failover Cluster Instances (SQL Server) using InfoSphere Data Replication Change Data Capture (CDC) on Windows Server 2012 Introduction As part of the SQL Server AlwaysOn offering, AlwaysOn
Continuous Availability Suite: Neverfail s Continuous Availability Suite is at the core of every Neverfail solution. It provides a comprehensive software solution for High Availability (HA) and Disaster
Extreme Networks Security Upgrade Guide 9034868 Published July 2015 Copyright 2012 2015 All rights reserved. Legal Notice Extreme Networks, Inc. reserves the right to make changes in specifications and
Deploying Remote Desktop Connection Broker with High Availability Step-by-Step Guide Microsoft Corporation Published: May 2010 Abstract This guide describes the steps for configuring Remote Desktop Connection
Executive Brief Infor Cloverleaf High Availability Downtime is not an option Gain value from Infor by: Delivering continuous access to mission-critical systems and data Providing uninterrupted continuity
Implementing Microsoft Windows Server Failover Clustering (WSFC) and SQL Server 2012 AlwaysOn Availability Groups in the AWS Cloud David Pae, Ulf Schoo June 2013 (Please consult http://aws.amazon.com/windows/
Availability Guide for Deploying SQL Server on VMware vsphere August 2009 Contents Introduction...1 SQL Server 2008 with vsphere and VMware HA/DRS...2 Log Shipping Availability Option...4 Database Mirroring...
High Availability Essentials Introduction Ascent Capture s High Availability Support feature consists of a number of independent components that, when deployed in a highly available computer system, result
Modular Messaging Release 4.0 Service Pack 4 Whitepaper: Support for Active Directory and Exchange 2007 running on Windows Server 2008 platforms. April 2009 2006-2009 Avaya Inc. All Rights Reserved. Notice
Backup Server DOC-OEMSPP-S/6-BUS-EN-21062011 The information contained in this guide is not of a contractual nature and may be subject to change without prior notice. The software described in this guide
IBM Security QRadar SIEM Version 7.2.6 High Availability Guide IBM Note Before using this information and the product that it supports, read the information in Notices on page 35. Product information This
Disaster Recovery System, page 1 Access the Disaster Recovery System, page 2 Back up data in the Disaster Recovery System, page 3 Restore scenarios, page 9 Backup and restore history, page 15 Data authentication
Contingency Planning and Disaster Recovery Best Practices Guide Perceptive Content Version: 7.0.x Written by: Product Knowledge Date: October 2014 2014 Perceptive Software. All rights reserved Perceptive
RingStor User Manual Version 2.1 Last Update on September 17th, 2015 RingStor, Inc. 197 Route 18 South, Ste 3000 East Brunswick, NJ 08816 Page 1 Table of Contents 1 Overview... 5 1.1 RingStor Data Protection...
Dell High Availability Solutions Guide for Microsoft Hyper-V www.dell.com support.dell.com Notes and Cautions NOTE: A NOTE indicates important information that helps you make better use of your computer.
VPN Hello and welcome. In the VPN section we will cover the steps for enabling the VPN feature on the Allworx server and how to set up a VPN connection to the Allworx System from your PC. Page 1 VPN The
Parallels Parallels Virtuozzo Containers 4.6 for Windows Upgrade Guide Copyright 1999-2010 Parallels Holdings, Ltd. and its affiliates. All rights reserved. Parallels Holdings, Ltd. c/o Parallels International
Disaster Recovery for Oracle Exalogic Elastic Cloud WITH ORACLE EXADATA DATABASE MACHINE Oracle Maximum Availability Architecture White Paper May 2011 Maximum Availability Architecture Oracle Best Practices
EMC NetWorker Module for Microsoft for Windows Bare Metal Recovery Solution Release 3.0 User Guide P/N 300-999-671 REV 02 Copyright 2007-2013 EMC Corporation. All rights reserved. Published in the USA.
MANJRASOFT PTY LTD Aneka 3.0 Manjrasoft 5/13/2013 This document describes in detail the steps involved in installing and configuring an Aneka Cloud. It covers the prerequisites for the installation, the
Microsoft Exchange 2003 Disaster Recovery Operations Guide Microsoft Corporation Published: December 12, 2006 Author: Exchange Server Documentation Team Abstract This guide provides installation and deployment
Virtual Web Appliance Setup Guide 2 Sophos Installing a Virtual Appliance Installing a Virtual Appliance This guide describes the procedures for installing a Virtual Web Appliance. If you are installing
CHAPTER 14 This chapter describes the Cisco Identity Services Engine (ISE) database backup and restore operations, which include Cisco ISE application configuration and Cisco Application Deployment Engine
Administration GUIDE SharePoint Server idataagent Published On: 11/19/2013 V10 Service Pack 4A Page 1 of 201 Getting Started - SharePoint Server idataagent Overview Deployment Configuration Decision Table
Configuring MDaemon for High Availability This document is intended to provide a general outline of the steps that are required to configure MDaemon for high availability. Modifications may be required
Architectures Haute-Dispo Joffrey MICHAÏE Consultant MySQL 04.20111 High Availability with MySQL Higher Availability Shared nothing distributed cluster with MySQL Cluster Storage snapshots for disaster
GRAVITYZONE HERE Deployment Guide VLE Environment LEGAL NOTICE All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, including
Deploy App Orchestration 2.6 for High Availability and Disaster Recovery Qiang Xu, Cloud Services Nanjing Team Last Updated: Mar 24, 2015 Contents Introduction... 2 Process Overview... 3 Before you begin...
CA ARCserve Replication and High Availability for Windows Microsoft SQL Server Operation Guide r15 This documentation and any related computer software help programs (hereinafter referred to as the "Documentation")
EMC Avamar 7.0 for Windows Server User Guide P/N 300-015-229 REV 04 Copyright 2001-2014 EMC Corporation. All rights reserved. Published in the USA. Published May, 2014 EMC believes the information in this
APPENDIXE This module provides basic guidelines for the (VCS) configuration in a Subscriber Manager (SM) cluster installation. It assumes basic knowledge of the VCS environment; it does not replace the
HP ProLiant DL380 G5 High Availability Storage Server installation instructions *5697-7748* Part number: 5697 7748 First edition: November 2008 Legal and notice information Copyright 1999, 2008 Hewlett-Packard
Technical white paper HP Device Manager 4.6 Installation and Update Guide Table of contents Overview... 3 HPDM Server preparation... 3 FTP server configuration... 3 Windows Firewall settings... 3 Firewall
CHAPTER 16 Troubleshooting Failover in Cisco Unity 8.x This chapter describes methods for troubleshooting Cisco Unity failover. See the following sections: Failover Configuration Wizard Does Not Finish
High Availability Storage High Availability Extensions Goldwyn Rodrigues High Availability Storage Engineer SUSE High Availability Extensions Highly available services for mission critical systems Integrated
Attachment Save for Exchange Administrator s Guide document version 1.8 MAPILab, December 2015 Table of contents Intro... 3 1. Product Overview... 4 2. Product Architecture and Basic Concepts... 4 3. System
Security Provider Integration RADIUS Server 2015 Bomgar Corporation. All rights reserved worldwide. BOMGAR and the BOMGAR logo are trademarks of Bomgar Corporation; other trademarks shown are the property
DEPLOYMENT GUIDE CONFIGURING THE BIG-IP LTM SYSTEM WITH FIREPASS CONTROLLERS FOR LOAD BALANCING AND SSL OFFLOAD Configuring the BIG-IP LTM system for use with FirePass controllers Welcome to the Configuring