Both JBOD and RAID have their strengths and weaknesses in data storage – and both have their advocates among storage professionals.
To be sure, there are many ways to configure the physical disks on which your data archives are stored. So many, in fact, that it can be very confusing deciding on which storage architecture is right for you.
Here at Enterprise Storage, we’ve previously given you guides on this topic, which explain that AHCI, IDE, and RAID all have their strengths and weaknesses.
Today, we’re going to cover yet another type of data storage architecture – JBOD and how it compares with RAID. We’ll explain how these architectures work, how they differ from one another, and how to make a decision about which is right for you.
What is JBOD?
As with many of the acronyms used by IT professionals, JBOD is a technical-sounding term that actually stands for a mundane phrase. JBOD stands for Just a Bunch of Disks, or Just a Bunch of Drives.
This seemingly simple description hides a great deal of complexity, though.
JBOD systems, as the acronym suggests, are generally composed of a large number of individual hard drives and brought together in one housing. These units can offer huge amounts of storage – hundreds of terabytes, even in some commonly available units – and can be configured in a wide variety of ways to suit different purposes.
One of these configuration models – somewhat confusingly, in this context – is RAID. But in the majority of cases, JBOD systems are focused on providing a different functionality from RAID systems. JBOD enclosures are generally used to store large amounts of data for a defined length of time, before these same data can be optimized for long-term archiving.
Several aspects of the standard JBOD architecture lend it well to this purpose. One is the fact that data are generally written to JBOD disks in a sequential way, without the complex mirroring and parallelization steps involved in RAID systems. This means that data can be written quickly and efficiently to JBOD systems. Another advantage of these systems is that this method of writing helps to prevent disk fragmentation, and therefore improve system speed.
What is RAID?
RAID is likely to be more familiar than JBOD, because RAID has been around for more than a decade in various forms. Though there are many different types of RAID, they all rely on the same principle. RAID stands for Redundant Array of Independent Disks (RAID). It’s a data storage technology that combines two or more solid state drives or hard disk drives into a single unit.
There are several different ways in which this merging can be achieved, and each is described by a numbered RAID configuration. The most commonly seen of these are RAID 0, RAID 1, RAID 5, RAID 6 and RAID 10. Each of these configurations makes use of a different strategy for duplicating data and ensuring that it is not lost or damaged.
The popularity of RAID has stemmed from two factors. One is that many companies have looked at the serious data security risks that have evolved over the last year, and decided that their archiving systems need more protection. The other is that several regulatory frameworks – particularly in Europe and the US – require companies to prove that their data have been archived securely, and RAID provides a relatively cost-efficient way of doing that.
Is JBOD or RAID Best for My Company?
The most pressing question faced by most businesses, of course, will be choosing an archival architecture that provides a cost-efficient and secure way to store large amounts of data. As we’ve seen, both JBOD and RAID can provide this, but there are also significant differences between the models.
Similarly to the difference between NAS and RAID, the most important factor in choosing between JBOD and RAID is arguably complexity. JBOD offers a fairly straightforward way to archive huge amounts of data, and JBOD enclosures are typically much cheaper than dedicated RAID hardware. In contrast, RAID systems can be complex to design, oversee, and maintain, especially for smaller companies that lack in-house storage engineer expertise.
There is a major advantage to RAID, though: security. Almost all of the RAID levels make use of some form of data redundancy, in which multiple copies of a particular dataset are made in order to guard against natural disasters and intentional theft. Though tracking all these multiple copies can be complicated, they offer the best protection against cyberthreats currently available. For large organizations which hold similarly large amounts of sensitive data, this makes a RAID infrastructure all but necessary.
The Bottom Line
It’s not necessary, however, to choose between the two architectures. It’s more than possible, for instance, to use JBOD enclosures for short- or medium-term data archiving, and then run these data through your data archiving software as it is moved to a more secure RAID archive.
In this way, you get the best of both worlds – the speed and ease-of-use of JBOD, with the extra security provided by RAID.