Lead Image © jiawangkun, 123RF.com

Disaster Recovery for Entry-Level NAS

Near Miss

In virtually any office, and even in many private households, users face the challenge of storing data securely at a central location. No problem, you might think; after all, you don't need to wait for network attached storage (NAS) devices to be invented. NAS is a distinct type of storage that always shares the same basic feature set: It is integrated into the local network by Ethernet and then provides network drives for storing data with protocols such as NFS or CIFS. Professional models also support iSCSI or NVMe over fabrics (NVMe-oF), making them attractive for virtualization tasks.

Regardless of how NAS is used, though, in most cases this little device will become indispensable in everyday life and take on central importance. How critical a failure is depends on the specific situation. Even in a private household, it can be a real blow if vacation photos or backups of personal correspondence are lost. For businesses, the unavailability of network storage can even mean a threat to operations. You should therefore consider, especially in the context of business continuity, how to protect your organization against a failed NAS.

A fundamental distinction must be made between disaster recovery (DR) and high availability (HA). Because HA and DR are two different use cases, the challenges they face differ. With regard to legacy NAS devices, this article focuses primarily on the topic of preparing for catastrophic events (i.e., DR), and one thing is clear: Small office and home office (SOHO) devices from various vendors do not offer the level of DR functionality that you would like to see.

Redundancy vs. DR

HA relates to the operational concept of redundancy, where the goal is to provide a replacement for a temporarily failed device at short notice, ideally within a few seconds. Operational downtime is as short as possible and accordingly mitigates the serious consequences that a