Storage and Disaster Recovery FAQ
Here are some of the most common questions on storage and disaster recovery (DR), as provided by our authors for this special report.
Posted September 15, 2003
Storage
Q. What are some of the most common storage and backup options?
A. There is no single solution for everyone. Depending on company size, disks and tape can be appropriate. Some companies are moving to centralized storage, a potentially expensive option although network-attached storage (NAS) devices are now available for as low as $2,000. Many companies believe that using distributed data deposits through direct attached storage (storage that is directly located within a server) is still the best method, though.
Q. What are some of the new storage technologies that can be used to help with DR?
A. New technologies such as Serial Advanced Technology Attachment (Serial ATA, or SATA), Internet small computer serial interface (iSCSI), and Windows Server 2003, along with advances in current technologies such as Fibre Channel, make access to a more streamlined and secure storage approach readily available to organizations of all sizes.
Q. What is Fibre Channel?
A. Fibre Channel technology allows data transmission at rates of up to 1 or 2 Gigabits per second (Gbps). It is used for connecting servers to shared storage devices and for interconnecting storage controllers and drives. Although a 10 G-bit switch has been in the works for some time, a 4 G-bit switch was recently ratified and will likely be more popular in the short run.
Q. What is RAID?
A. Redundant Arrays of Independent Disks use two or more disk drives to mirror data.
Q. What is a geocluster?
A. Geocluster is short for geographic cluster. A geocluster is made up of a bank of servers operating in tandem to provide load balancing and fail-over services. These servers are situated in separate physical locations, sometimes spanning large distances. Geoclusters have been too expensive for small- to medium-sized firms, but iSCSI technology is helping to lower the cost.
Q. How often should backups occur?
A. This will vary according to the size of your organization and the type of data involved, but some experts recommend full system backups on the weekend, with incremental backups every night.
Q. Where should backups be stored?
A. Keeping complete backups at multiple sites will be sufficient for most companies, but you'll need to make sure that they are safe from both theft and hacking. Some companies prefer to keep their backups with outsourced data protection companies like Iron Mountain.
Q. How often should backup media be replaced?
A. Some who use tape and rewritable optical discs replace them after about two dozen backups, even if manufacturers say they will last much longer.
Q. What's wrong with using tape backup for disaster recovery? It's cheaper than remote replication and mirroring.
A. There's nothing inherently wrong with using tape backup, particularly if you're a small- or medium-sized business with a limited budget. However, with the availability of affordable Storage Over IP solutions, you can leverage the benefits of data replication over longer distances for a more sound disaster recovery strategy.
Q. How can my company decide what data needs to be backed-up?
A. Perform a cross-departmental analysis to find out how your company is really using data. Then you can make sure you have appropriate backup methods and possibly save money on new and existing storage options that might be unnecessary.
Q. What is a "hot backup"?
A. "Hot backup" servers are on-site and constantly replicate the work being done by the main servers. While not an enterprise-wide solution, it makes good sense to keep hot backup servers if you have a critical server or server farm. However, hot backups are an expensive solution.
Disaster Recovery
Q. What is the first item an auditor will require of your business in an audit?
A. Documentation detailing the processes and methodologies used for disaster recovery or business continuance. Developing such documentation is the de facto standard for any business continuity or DR strategy.
Q. What are the key elements of a DR plan?
A. A DR plan should be documented with key staff and contact information, locations of backups, recovery procedures, communications procedures, and a testing schedule. Additional elements may be necessary depending on company size.
Q. How often should DR plans be tested?
A. Quarterly tests are recommended, although experts such as Jon Toigo recommend testing as often as possible, whether by doing a paper walkthrough or an actual implementation of procedures.
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