is CDP right for the SMBs?
Posted in General, Storage Applications, Platforms, Advisor - Steve Rogers by Steve RogersWith Continuous Data Protection CDP, software and appliances getting much press these days. SMBs and SMEs are asking if CDP might be right for them. So what is CDP for SMB? The answer is: Whatever you need it to be.
Perhaps the vendor who released the first CDP product purposely associated the acronym with Enterprise-class data; but as I look further into the CDP term and the solutions that are evolving, it seems to be morphing just as when the SAN term first appeared, it was primarily Fibre Channel. As you look at how SANs are being described today, there are now IP-SANs, soon to be SAS-SANs, as well as even the broader useage of the term relating to any storage that is “networked.” over any medium, albeit Block or File.
CDP as a term, is evolving and so are the solutions coming to market.
CDP, as currently available whitepapers define it, provides a recovery point objective or RPO (sounds a little too paramilitary for me…) or essentially where the user can quickly rewind their data to any point in time, so there are no gaps in time since the last backup, or point-in-time copy –as in the more established backup methods. The recovery point of CDP can be as granular as the last I/O. Quite a grandiose promise I think; not to mention, the overhead and price tag that goes along with it. But don’t let the purist’s definition scare you away. More cost effective solutions and appliances are emerging in this space, more will soon follow.
When an SMB considers a CDP product it is important to understand what their current and future needs are, if any, for continuous data protection and recovery.
Is CDP really necessary in the SMB or in distributed offices? Certainly critical data can exist anywhere it is necessary for running the business, such as: local transaction oriented databases, reference catalogues, or even applications the entire office might be dependent upon. But there is also other important data in remote offices and in mobile work forces as well, such as what might be considered on someone’s laptop. So does CDP fit there as well? IT depends on ones tolerance for recovery.
As a point of debate, if I purchase a piece of client software that I load on my laptop that constantly monitors and logs the changes to the files and folders that I indicate, and when I am connected to the network these files are updated to a central file server on the network; and I don’t have to think about it, or consciously do anything to make this happen; is that not continuous data protection from the user’s perspective? If you agree, there are a variety of inexpensive software applications that can do just this for laptops and desktop clients. As long as you are ok with the possible loss of some since last save.. This may be perfectly acceptable.
So what would a small business do if they have some small to mid-sized servers that have applications running with continuously changing data that need to be protected? Will CDP also protect the databases and mail applications that manage block-level data Exchange and SQL. A word of caution here, while CDP can provide up to a single I/O recovery point, that point may also be corrupted. It can be a tedious process to find the point where the database was consistent. However, all databases provide checkpoints and rollback logs to recover transactions to what ever consistency point you set.
Does this mean you need a different solution for laptops than for your small servers at your remote offices? Maybe, depends on your budget how many laptops you want to protect and what level of recovery you want.
Less expensive CDP Appliances for SMB are coming that can provide CDP in a variety of ways in a single appliance, protecting for block applications as well as File Data even with open files and locked files, and snapshot capability and possibly even BMR. But with a lesser price tag, there will tradeoffs, most likely lesser recovery points then their bigger enterprise-priced versions; but for SMBs and remote offices, I think that will be good enough.
Lastly, in regard to implementation of a CDP solution. One finer point that SMBs may overlook relative to the CDP model, is that the applications and files have to be completely copied over to the CDP target before the continuous I/O monitoring and shadowing can begin. This can take a long time depending on the amount of data you have. It is a good idea to schedule this with your environment offline until these copies are complete; then you can start the CDP with minimal disruption.
SR
October 3rd, 2006 at 2:38 pm
Hi Steve,
It seems your want to address to issue of data recovery options for SMBs. Good. You offer that SMBs might not need a system where each and every write is saved; that a rapid-fire variant of periodic backup would be more appropriate, weighing risks and costs. Fine. But to bend the meaning of ‘continuous’ to sometimes mean ‘every so often’ or ‘whenever there is a connection available’ - that to me is a problem. Any word can mean anything that we agree on, but for it to mean anything at all, we’d better stick to one meaning. Marketers will try to label anything with a TLA that smells like big boys stuff, but in the end we are all victims. Remember Token Ring’s Source ROUTING, which had nothing in common with routing but sounded so good? No wonder IT is infamous for using unintelligent language.
I’m sure there are good descriptive terms for the type of discontinuous, high frequency, nearest opportunity data protection that surely could benefit SMBs.
October 24th, 2006 at 1:07 pm
all good points;but again, to your point, if the term SAN stuck to its original technology and intent we would not be talking about SAS-SANs and IP-SANs as we are today.
I personally feel, CDP is way too broad of a term to keep it relegated to the high-end of the market.
if this discussion thread causes even one poor SMB owner to ask more questions about what CDP solutions would do for them; and perhaps prevent them from purchasing an overpriced over featured solution for their needs, then I say “bring on the confusion.”
SR