What you will learn in this tip: Any storage or backup admin who's responsible for a remote backup system that involves tape can relate to the challenges tape backup can present. This
tip will look at remote backup solutions other than tape, such as hosting applications offsite, remote replication and the cloud.
Data backup for remote offices and branch offices (ROBOs) can be tough. The first issue is there's usually no one with sufficient IT skills at the remote site to help when things go wrong or, even worse, there is someone there who believes they have IT skills and is causing problems. Other common challenges include:
- Backup media not taken offsite for storage, causing a potential risk for data loss
- Improper tape handling procedures
- Media not stored or secured properly (e.g., left in someone's car on a hot summer day)
- Media stuck in the tape device, but no one onsite knows what to do
- Insufficient network bandwidth, or too much data to back up to the head office
This is just a partial list of the many things that can go wrong with remote data backups and, in some cases, have lead to painful recovery delays and data loss. Many remote offices -- especially small ones -- tend to fall under the radar when it comes to data protection. Following are some options that offer an alternative to tape backups for remote sites.
Alternatives to tape backup systems
Appropriate tape backup replacement options depend on the size of the remote office, the amount of data hosted and the rate at which that data changes. For the purpose of this discussion, we'll assume that if a remote location has a large enough IT footprint to generate or handle significant amounts of data; it should have skilled IT resources onsite, and benefit from the same type of data backup infrastructure as the main office. The focus is therefore on smaller offices.
Host applications offsite
One of the first options to eliminate data backup to tape at a remote office is to not have data at that location. Depending on the nature of the applications used by that location, it might be advisable to move all IT systems to a nearby hosting facility that provides managed IT services or at least has IT support staff onsite to assist with backups.
Leveraging Web-enabled applications or virtual desktop technology such as Citrix XenDesktop or VMware View also provides an opportunity to host applications from a location other than the remote office where data can be adequately protected.
Local and remote replication
In instances where the data set used by the remote site is small enough or subject to a low change rate, there might be an opportunity to leverage host-based or storage array-based data replication. For example, NetApp Snapshot can be used to create multiple local data snapshots in lieu of tape backups, and SnapVault can be used to replicate local snapshots to a remote NetApp storage array for offsite data protection. This effectively eliminates the need for local tape backups and the need to take backup tapes offsite for disaster recovery.
Deduplication with remote replication
When the amount of data in use at the remote office becomes large enough to create challenges with remote replication or when network bandwidth limits the amount of data that can be replicated daily, data deduplication technology can be an alternative. Backup software will make a new copy of a file when it changes regardless of the amount of data that has changed. Backup data provides some of the best reduction levels with deduplication since it contains a large amount of identical byte sequences that can be replaced by pointers (this is the basic function of deduplication).
In the context of a remote backup system, deduplication can be leveraged in two ways. The first step is to replace the tape devices used by the backup software with a deduplication-enabled disk array; two examples of this technology include EMC Data Domain and Sepaton Inc., but there are many others. These disk arrays can achieve high levels of data reduction making them ideal replacements for tape media. The second step is to leverage the remote replication capabilities provided by these devices to replicate the reduced data set resulting in much less data being transmitted over the network.
It should be noted that the NetApp storage arrays mentioned earlier also have data deduplication capabilities. This offers the ability to combine snapshot, deduplication and remote replication technology in a single solution.
As an added bonus, WAN optimization appliances can be added to the remote site and replication target site to further reduce the amount of data sent across the network. This technology can be used not only with remote replication but also in conjunction with disk-based deduplication. WAN optimization works a lot like disk-based deduplication by identifying identical data sequences and replacing them with pointers that are reassembled at the receiving end. Some examples of WAN optimization appliance vendors include Cisco Systems Inc., Hewlett-Packard Co. and Riverbed Technology, to name only a few.
Even though WAN optimization appliances may be seen as something just for larger organizations, it's possible that a remote office with few employees could handle enough data to create backup challenges. If you have limited bandwidth between the replication source and target, a WAN acceleration device can be the answer if bandwidth is too expensive or simply unavailable.
Cloud backup for remote offices
No discussion on remote backup systems or offsite application hosting would be complete without mentioning cloud backup. This computing style is generating a lot of interest and there's a growing number of providers offering cloud-based data protection. Cloud offerings can also be leveraged to simply host the application and rely on the provider for data protection and backup as part of the service-level agreement; Amazon S3 Storage, Salesforce.com CRM solutions and Microsoft Business Productivity Online Services (BPOS) are some examples of cloud-based offerings that can eliminate the need for remote-office tape backups.
Every remote office is different and has unique needs, depending on the amount of data to be backed up and other factors. When deciding which is the best remote backup system for your organization, your decision should be based on how critical the data is, whether or not an offsite copy is needed and how poorly the local tape solution is working.
About this author: Pierre Dorion is the data center practice director and a senior consultant with Long View Systems Inc. in Phoenix, Ariz., specializing in the areas of business continuity and DR planning services and corporate data protection.
This was first published in February 2011