Is it too expensive for an enterprise to store lots of email for many years? On this blog I have been arguing that the law motivates enterprises to keep email generously. But generous retention (many records many years) raises questions about cost.
Earlier on this blog, I have aired arguments about whether cloud computing or content addressable storage (creates an in-house cloud) are effective technologies for archiving email economically.
One commenter argued that the alleged allure of content addressable storage (CAS) is just vendor hype.
To that, my friend Greg Smith at Messaging Architects responds:
“It is true that the cost of data centers, power, rack space and environmental conditions is a big cost to take into account when evaluating storage costs. But too often the thought when organizations are looking at storing terra bytes of data is to look at traditional storage mechanisms such as a SAN. Although a SAN is more economically feasible than local storage, it still requires the overhead of redundant drives for data protection . . . so that in effect some systems running a RAID 6 environment with an 8 drive array have a 25% operating overhead.
“Contrast content addressable storage designed for secure, in-house, long term storage. Since it does not employ a traditional file system, it does not have the limitations or constraints of a traditional system. In fact CAS systems, which can provide storage for under $3 / GB, are designed to replicate and validate data to ensure that:
* corruption and disk failure do not destroy data, and
* in the event of hardware failure, replacement of hardware is not the lengthy rebuild process that would apply to a SAN.
“How does CAS compare with storage in an external cloud provider? External cloud storage costs are low, and it is difficult for any form of in-house storage to compete with those low costs. However, what remains to be seen is whether the accessibility and security of data in the external cloud will be satisfactory. Let’s not forget that a cloud looks solid enough from the ground, but if you fly through it, it becomes translucent.
“Sometimes being able to physically touch something provides more assurance of its existence and accessibility. Still, that perception may change over time.
“On the subject of external cloud storage, one other question is data ransom. After you have stored many terra bytes of valuable data in a vendor’s cloud, the vendor will see that it can raise prices. When it does that, there is no choice but to pay these higher ongoing prices, as the cost to move that data in-house or to another provider may be prohibitive.”