Risks associated with transporting storage media & how to deal with them.
The point is this: When data on tape or disk is removed from a secure data center, where it was created in a hardened and protected library, risk potential must be evaluated and dealt with, or the consequences can be severe.
Where do these risks lie? Well for one, when media is removed from a secure data center, whether tape or disk, it can be dropped, stolen, or exposed to environmental conditions such as extremely high or low ambient temperatures or humidity levels. During transit, the media is also exposed to the potential for loss or theft, as the examples above indicate. And, if the facility the media will be stored in is not as physically or environmentally secure as the original data center, media can be similarly compromised.
Tiered Backup Storage: The Media Is the Message
To limit risks associated with mobile media, set up a tiered approach to mobile backup storage where the most critical data marked for removal (generally data required for business continuity or regulatory compliance) is stored on the most secure media, under the most secure conditions--and shipped securely as well. More risks can be taken with data that is less valuable, and so on.
A healthcare provider mandated to protect the privacy of patient data under the Health Insurance Portability and Accountability Act (HIPPA), for example, needs to use the most secure media when storing patient records. The data needs to be encrypted and written to media, then stored appropriately--whether onsite or off. Data pertaining to other operational areas may be less sensitive and treated in kind. Similarly, in the financial services industry, the previous six month's of data may receive the highest security treatment, with less and less security needed as the data ages.
A side benefit of a tiered mobile backup storage model that relegates the highest levels of protection to the most important mobile media is that it lets organizations minimize storage costs. Higher cost, higher security media can be recycled as security requirements for the data contained on them diminish, and lower cost media can be leveraged for long-term archival storage of less sensitive data.
Mixing Mobile Media To Meet Physical Security Needs
Three types of media can be used to transport data from a library to a remote storage facility. These mobile media include tape; CD, DVD, and disk; and RAID disk packs, where each meets a different need. To achieve the greatest flexibility in creating a tiered mobile storage infrastructure, and the best match of media to data protection requirements, requires storage libraries or data centers that support multiple media types.
Tape, such as LTO, is the lowest cost choice and is more resilient than standard disks. On the other hand, if a tape is damaged during transport all data on it is generally lost. Disks are less sensitive to humidity and environmental dust than tape because of their enclosed containers, but are typically more expensive and more at risk for shock damage and data loss during transport, because disk reading heads are in contact with the media. This is not the case with all SATA; select SATA disk rests the head above, not on, the media, protecting the data better than standard disk. Another advantage to disk: data on a damaged disk may be recovered.
Deciding whether to use tape or disk for transporting backed up data is really an exercise in balancing risks. Are shockproof containers available? Is the media being transported during hurricane season on the East coast or the Gulf Coast? Is the secondary storage facility located in a dry desert climate? Will the data be stored for long periods of time on the mobile media or will it be offloaded to a different media type?
For optimized protection--but at a higher cost than either tape or ATA disk--use RAID disk packs, writing the data using redundancy (such as RAID 1+0 or RAID 5). With redundant data stored across multiple disks built into every pack, even if one disk is damaged beyond repair, the entire data set can still be rebuilt. Furthermore, RAID disk packs that are shock-mounted are also more resistant to damage if dropped than either tape or normal disk. Restoring data from RAID disks can also be easier and faster, a capability that can be critical for business continuity.
But rather than choosing a single mobile media type, balance costs and benefits by relying on a combination of media. In a financial institution, for example, the most recent data may be stored and transported on RAID disk, older data on ATA disk, and the oldest data on tape. Or, RAID disks may be used for transporting all backup data to secondary sites, and once there, data can be offloaded to either tape or disk at those sites. Again, the key to a successful tiered backup storage model like this is ensuring that the data center can support multiple mobile media types, on a single platform if possible, to simplify data center management.
It is important to note that whatever practices and media are used for transporting data out of data centers, they must be available for getting that data back into the data center for a restore--and then back again to the secondary storage site once the restore is complete.
Protecting Data On Mobile Media Requires Encryption
No matter how robust the physical security procedures and media used while transporting data, theft or loss is always a possibility--as it is for backed up data stored anywhere. To guard against illicit data use, consider encrypting data stored on mobile media using secure algorithms; some encryption algorithms, such as AES 256, are virtually unbreakable.
Large quantities of data can be encrypted by the backup software before being pushed out to storage media. However, this has multiple drawbacks. First, it demands enormous amounts of CPU power. Second, it imposes a time penalty as encrypting the quantities of data backed up to LTO and similar tape can take much longer than most backup windows permit. Finally, encryption requires about twice as much tape or disk capacity. Why? Because encrypted data cannot be compressed. All these factors limit the use of encryption as it is currently available.
Emerging encryption solutions, however, address these problems by encrypting data at the hardware level. It's much, much faster, and it off-loads the server CPU that would otherwise be consumed by the complex calculations involved in encrypting data. Ideally, the hardware-level encryption would be preceded by hardware-level compression, so that half the number of tapes (or amount of disk) would be needed, as opposed to the quantities of media used when data is encrypted without compression. With hardware-level compression and encryption, you can store compressed, encrypted data to tape, and (in tape format) to removable RAID.
In organizations requiring high-level data protection, encryption is becoming increasingly desirable and even necessary, given the loss of millions of customers' personal data, increasingly strict regulations, and the ever-present risk of litigation.
Physical protection, encryption, hardware-based security: these tools are available for protecting mobile media. By integrating all in a tiered backup storage infrastructure, organizations can achieve the levels of protection needed to meet business continuity, regulatory, industry, and customer-driven requirements. In a world where risk management has become essential from both business and compliance perspectives, the time for addressing these needs is now.
Nathan C. Thompson is CEO, of Spectra Logic Corporation, Boulder, CO
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|Title Annotation:||Disaster Recovery & Backup/Restore|
|Author:||Thompson, Nathan C.|
|Publication:||Computer Technology Review|
|Date:||Aug 1, 2005|
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