Email Continuity Options

Compare Exchange Server Continuity Options
 

Due to budget and resource constraints, many small and midsized businesses are forced to make do with tape backups as their primary solution for disaster recovery. While backups can help prevent permanent data loss, they don’t provide continuity. In other words, tape backups don’t allow end users to access and send emails and attachments during an outage. Plus, they won’t help if an organization needs to take its server down for routine maintenance (i.e., planned downtime).
 
On the other end of the spectrum, larger organizations with bigger budgets are able to invest in and maintain high-availability server configurations, including clustering and replication systems. In many cases, these high-end technologies provide end users with almost-instant access to their messages during an outage and can also be used during planned server downtime.
 
Every organization does not have the same needs, so it is important to consider all the options available when it comes to email continuity and disaster recovery. Different companies have varying thresholds for cost, downtime and recovery time. The chart below provides an overview and analysis of the various options:
 
MethodCostTime Recovery Time
Tape Backup/Recovery$****Hours to days
Clustering$$**Minutes to hours
Replication$$$$**Minutes to hours
LiveOffice Email Continuity$*Minutes


Option 1: Microsoft Exchange Backups
 

Most small to medium-sized organizations run internal email servers and back them up routinely. Unfortunately, these traditional backup methods create a false sense of security. Although they are a reliable source of historic content, backups fall short for email continuity in several ways:
 
  • The recovery process can take anywhere from hours to days
  • End users are unable to send and receive mail during the recovery process
  • Data that was created after the last backup is permanently lost. For example, if you run backups daily, all data between the last day’s backup and the outage cannot be recovered.
     
But, more importantly, what do users do to communicate while Microsoft Exchange is down and the IT department is scrambling to recover? Many users start using their personal email accounts (e.g., Gmail, Hotmail or Yahoo!), which appears unprofessional and is often unrecognizable to the recipients. Plus, using non-corporate email accounts may circumvent organizations' compliance policies and industry regulations.


Option 2: Exchange Server Clustering
 

Clustering is used to distribute Microsoft Exchange’s load between a number of servers. By splitting the workload among several servers, organizations can protect Exchange Servers during cases of system failure. While clustering is an attractive architectural decision, it’s not without difficulties:
 
  • Cluster configuration and maintenance is complex and time consuming
  • Clustering requires licensing and setting up multiple Microsoft Exchange Server(s)
  • Cluster servers must be maintained with the same operating system/Exchange version
  • Clustering generally requires cluster-certified IT staff
  • Testing cluster configurations often necessitates downtime
  • Clustering helps with server failure, but not site-wide failure
     
The rising cost and complexity of clustering prevent most resource-constrained organizations from actively pursuing it for an email continuity solution.


Option 3: Site Replication
 

Software replication solutions offer an added layer of protection over clustering and actively copy data to secondary locations in case of a complete site failure. This design may also require:
 
  • Additional servers, operating systems, Microsoft Exchange Server licenses and any application software needed to clone the primary email server(s) to the secondary site
  • Additional software, which is often required on all user desktops to facilitate email continuity
  • New highly available disaster recovery storage for replicated Microsoft Exchange environment
  • Provisioning new bandwidth between primary and secondary sites to facilitate replication
  • Increased overhead costs for leasing, heating, cooling and power of secondary data center(s)
     
Although site replication gives organizations additional peace of mind, it also comes with risks. Failover is not immediate, and reverting back to the primary site can result in email data loss. Like clustering, software replication solutions are generally out of financial and practical reach for smaller IT departments.