Posted by: cgibney
Data storage management, WAN Optimization / WAFS
One of the common questions I am getting from IT people that I meet with is how can they protect remote offices, typically those with no local, at least officially anyway, IT staff. It is important to accept upfront that you may need a couple of solutions to address this challenge. This is especially true if you have remote offices that vary in size. There may be local databases and, more often than not, local file servers.
The first option is to eliminate the problem by eliminating the local need. Products like Citrix or Windows Terminal Server can eliminate the need for local applications and a wide area file system (WAFS) can eliminate the need for local file servers. The Citrix/Windows Terminal server solutions are best explained by those two companies so we’ll spend our time on WAFS. WAFS essentially places a cache at the remote site. At a high level, this cache is a server appliance with a small local disk that can replicate changes as they happen to a central server at a primary data center. The most frequently accessed data is stored on the remote file server, which serves up data to those users in a local fashion and at local performance. Typically, proprietary but enhanced network protocols are utilized to get higher performance on data transfers for data that is not in the remote cache. Some of the WAFS companies are also providing the ability to utilize data deduplication on the network, in a similar fashion to how some disk-to-disk backup products use data deduplication to optimize storage. NAS that can do data deduplication would be an ideal central NAS for this environment since typically there is a high level of file redundancy between remote offices and the primary data center.
From a data protection standpoint, the centralized repository for all the remote cache’s data is now also a server at your primary data center and can fall under the umbrella of your normal protection scheme. Other advantages to WAFS is that it can eliminate the need for buying additional servers and storage for remote offices, delay the need for bandwidth upgrades and can even enable better collaboration between offices.
Another option is to use replication. This is ideal for sites that in addition to a remote file server also have some remote database applications or email, especially if there are just a few of this type of sever present. While most data replication products are considered for disaster recovery solutions, they also make for an ideal remote or branch office backup solution. With these products all data is replicated as it changes to a centralized disk at the primary site. This disk can then be mounted to a backup server and backed up locally at the primary data center. Cost can be a concern if the local server count is more than just a few servers and you are not leveraging the other value points (disaster recovery and failover) of replication. Also, unless your data replication solution can produce snapshots to freeze moments in time or you can leverage snapshot technology by replicating to storage that supports it at the primary data center, be aware that if you do experience corruption at the remote site, you will then very quickly replicate that corruption to the primary site.
If you don’t need the near instant protection of WAFS or replication you can also leverage some D2D solutions to perform a backup locally and utilize the D2D solution’s replication capability to send that data to a similar device at the primary data center. This typically makes sense when you have a fairly large data set or number of servers and maybe a small remote IT staff. It will also almost certainly require a data deduplication device, as straight disk-to-disk backup will not work well for remote backups. You need to be able to deploy a D2D solution that can leverage data deduplication. Standard backup to disk essentially consists of several large backup files. Those files are typically created too fast and are too large to be copied across the common WAN segment in time to meet the nightly backup window. Data deduplication appliances on the other hand only have to send the changed block between the backup jobs, greatly reducing the WAN requirement. Also, you now have the data locally at the branch office instead of only at the primary data center, allowing for faster recovery at the branch if needed.
In the past four or five years, we have expanded from hardly any options for remote office data protection to many. Which of these solutions you deploy is a function of budget and business requirement, and in some cases it may make sense to blend the solutions. Assessing the needs of the remote offices while focusing on the business realities at the primary data center, will help you make those choices.