Warner Estates deploy real time replication of core applications to provide resilience
Customer Overview
Warner's has two core business applications that demand 100% availability day and night, 7 days a week: MS Exchange and a bespoke accounts system running on a proprietary database.
MS Exchange was essential to maintain a high level of communication with their clients and also it was the repository of business critical information used by 200 staff located at eight regional offices.
The database application provides their accounting and billing systems sand is the financial hub of the organisation.
Both applications are running on dedicated server hardware with direct attached storage. The Exchange database was 400GB in size, the accounting system occupied 40GB.
The Objective
To provide server resilience for both applications that could be invoked upon production failure with minimal service disruption. It was also the long term aim to roll the solution out to other key applications.
The Solutions
- Install a new high specification hot spare server platform running VMware ESX Server.
- Install a StoreVault S500 NetApp filer to provide 3.6TB of available storage.
- Install DoubleTake real time replication software to replicate the two production servers.
Mode of Operation
Two virtual Windows environments were installed on the hot spare hardware platform. They were configured using iSCSI connectors to point to predefined LUNs on the network filer.
To minimise congestion, the LAN was segmented into two VLANs. One dedicated for iSCSI traffic, the other for all other traffic. Spare gigabit network interfaces in the two production server were connected to the iSCSI VLAN. One of the two available gigabit network interfaces on the network filer was also connected to the iSCSI VLAN. The other was connected to the general purpose VLAN.
DoubleTake replication software was installed on all four participating servers (physical and virtual). Replication was set up between each production environment and corresponding virtual backup environment.
Upon failure of either production system, DoubleTake would invoke the corresponding backup virtual environment and assume the identity of the production server.
All client computers were redirected to the backup virtual environment within seconds.
Fixed cost per machine
For a fixed monthly charge ISN can provide you with proactive support with guaranteed response times. After an initial one-time stabilisation of your IT environment, we cover all faults and errors.
Pre-paid hours
A flexible way to use ISN's services. Hours purchased can be used as telephone, remote control or on-site support. The more hours purchased, the lower the equivalent hourly rate.
Pay on use
Many organisations don't feel happy about committing to an annual contract, especially if their IT support requirements are small. ISN are happy to provide our expertise on an informal basis charged at an hourly rate.