HP ProLiant DL380G5-WSS 3.7.0 HP StorageWorks HP Scalable NAS File Serving Sof - Page 34

Virtual hosts and failover protection, Service and device monitors

Page 34 highlights

Virtual hosts and failover protection HP Scalable NAS uses virtual hosts to provide failover protection for servers and network applications. A virtual host is a hostname/IP address configured on one or more servers. The network interfaces selected on those servers to participate in the virtual host must be on the same subnet. One server is selected as the primary server for the virtual host. The remaining servers are backups. The primary and backup servers do not need to be dedicated to these activities; all servers can support other independent functions. To ensure the availability of a virtual host, HP Scalable NAS monitors the health of all network interfaces and the health of the underlying server. If you have created service or device monitors, those monitors periodically check the health of the specified services or devices. If any of these health checks fail, HP Scalable NAS can transfer the virtual host to a backup server and the network traffic will continue. After creating virtual hosts, you will need to configure your network applications to recognize them. When clients want to access a network application, they use the virtual host address instead of the address of the server where the application is running. Service and device monitors A service is a network service such as HTTP or FTP that is installed and configured on the servers in the cluster. HP Scalable NAS can be configured to watch specific services with service monitors. A service monitor is created on a virtual host. The service being monitored should be installed on all servers associated with that virtual host. When a service monitor determines that a service has failed, HP Scalable NAS transfers the virtual host for that service to a backup server. For example, if the HTTP service fails, HP Scalable NAS will transfer the HTTP traffic to a backup server that provides HTTP. HP Scalable NAS includes several built-in service monitors for monitoring well-known network services. You can also configure custom monitors for other services. A device monitor is similar to a service monitor; however, it is designed either to watch a part of a server such as a local disk drive or to monitor a PSFS filesystem. A device monitor is assigned to one or more servers. HP Scalable NAS provides several built-in device monitors. You can also define your own custom device monitors. 34 Introduction

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Virtual hosts and failover protection
HP Scalable NAS uses virtual hosts to provide failover protection for servers and
network applications.
A virtual host is a hostname/IP address configured on one or more servers. The
network interfaces selected on those servers to participate in the virtual host must be
on the same subnet. One server is selected as the primary server for the virtual host.
The remaining servers are backups.
The primary and backup servers do not need to be dedicated to these activities; all
servers can support other independent functions.
To ensure the availability of a virtual host, HP Scalable NAS monitors the health of
all network interfaces and the health of the underlying server. If you have created
service or device monitors, those monitors periodically check the health of the specified
services or devices. If any of these health checks fail, HP Scalable NAS can transfer
the virtual host to a backup server and the network traffic will continue.
After creating virtual hosts, you will need to configure your network applications to
recognize them. When clients want to access a network application, they use the
virtual host address instead of the address of the server where the application is
running.
Service and device monitors
A service is a network service such as HTTP or FTP that is installed and configured
on the servers in the cluster. HP Scalable NAS can be configured to watch specific
services with service monitors.
A service monitor is created on a virtual host. The service being monitored should
be installed on all servers associated with that virtual host. When a service monitor
determines that a service has failed, HP Scalable NAS transfers the virtual host for
that service to a backup server. For example, if the HTTP service fails, HP Scalable
NAS will transfer the HTTP traffic to a backup server that provides HTTP.
HP Scalable NAS includes several built-in service monitors for monitoring well-known
network services. You can also configure custom monitors for other services.
A device monitor is similar to a service monitor; however, it is designed either to
watch a part of a server such as a local disk drive or to monitor a PSFS filesystem.
A device monitor is assigned to one or more servers. HP Scalable NAS provides
several built-in device monitors. You can also define your own custom device monitors.
Introduction
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