The pros and cons of cloud storage are, to be sure, debated with great enthusiasm. For every advocate of public cloud storage, there appears to be a naysayer ready to run it down. For every dream migration of data to the cloud there appears to be a cloud nightmare lurking.
So what’s the real story? Is the cloud all bad or all good?
Like actual clouds, the answer is seldom black and white. Plenty of shades of gray are apparent when you look up to the sky or view the murky world of cloud storage. So let’s take a look at some of the primary cloud storage pros and cons.
Pros and Cons of Cloud Storage: the Pros
In brief, the pros of cloud storage revolve around scalablity, the value of offsite management, fast deployment, and lower upfront costs. Plus: in a world that always requires more – and more – storage capacity, cloud storage offers limitless additional capacity.
Pro – Offsite Management
The cloud enables off-site, online storage that somebody else physically maintains. This frees up attention for other priorities, particularly if you have a sound relationship with a reliable vendor at a reasonable cost.http://o1.qnsr.com/log/p.gif?;n=203;c=204655439;s=10655;x=7936;f=201806121855330;u=j;z=TIMESTAMP;a=20400368;e=i
“In some cases cloud providers may even be handling the logical aspect such as backups, data protection, securing and other items in addition to what you do to manage it,” said Greg Schulz, an analyst with StorageIO Group. “You can offload some physical on-site storage management tasks including acquisition, setup and configuration to the cloud.”
Pro – Connectivity
Gary Watson, vice president of technical engagement, Nexsan, pointed out one of the big pluses of the cloud is that it lets users freely share and access data at any time, from anywhere, from any device.
“The cloud connects the modern enterprise in a way that enterprise storage solutions have never been able to do,” said Watson. “With the right cloud storage, organizations can experience gains across operational efficiency, business agility, time-to-market and competitive advantage as well as decreased cost.”
Pro – Speed
Testing done by Mediatronics showed that when the cloud is supported by the right enterprise technologies, the speeds achieved can rival onsite scores. With a 1 Gbit pipe available, Mediatronics found that an enterprise could use 15 servers backing up data simultaneously for a total of 75 TB protected in the cloud using a Zetta.net service during one nightly backup window. This compares very well to backing up onto disk. The data transfer rate recorded by Mediatronics for the Zetta.net incremental backup transfer was 975 Mb/sec. That’s faster than a 5,400 rpm hard drive (800 Mb/sec) and very close to the rate of a 7,200 rpm hard drive (1064 Mb/sec).
Pro – Rapid Deployment
Kevin Liebl, vice president of marketing, Zadara Storage, made the case that the public cloud bypasses the old approach to adding storage: evaluating storage demands, requesting bids from vendors, product selection, POs, waiting on delivery, assembling the various storage assets, integration, testing and data migration, provisioning, etc. Impatient users typically would be told, “Winter is coming,” in response to questions about how long it might take to be able to access more storage.
Pro – Scalability
Scalability is another area where the public cloud rules. The various providers have done a good job in making vast amounts of storage capacity available on tap.
“Virtually unlimited capacity and often scalable performance are available in the public cloud,” said Liebl.
Pro – Storage Immortality
Not so long ago, storage managers bought shiny new storage arrays or massive tape libraries. At the time, they seemed so cutting edge – yet soon they gathered dust as obsolescence sets in. Did their hefty price tag ever really deliver the promised return on investment? In more than a few cases, the answer is a resounding no.
The public cloud offers a way to bypass the risk of purchasing soon-to-be-over-the-hill hardware. You pay for the capacity and performance you want, and the providers upgrade their environments to keep pace with state of the art – egged on by competitive pressures from other providers.
“The public cloud offers immortal storage in that your storage components are being upgraded in the background and after a few years your storage is not obsolete,” said Liebl.
Pro – Lower Upfront Cost
Evaluating, purchasing, building, provisioning and managing storage can be an expensive business. The allure of the public cloud is that it takes all this off your hands and doesn’t charge an arm and a leg. In many cases, a lot of that storage capacity sits idle. Often businesses with peak periods end up buying enough storage and performance to satisfy peak demand, yet 95 percent of the time that amount of storage and IO simply isn’t needed.
“The public cloud allows you to pay for what you use and comes with reporting to monitor your spend and storage usage, as well as IO activity,” said Schulz.
Pros and Cons of Cloud Storage: the Cons
In sum, the cons of cloud storage focus on compliance, overall lifetime costs, doubts about security, and speed issues. Bottom line: if a data set is absolutely critical to a company's continued existence, it typically is not stored only in the cloud.
Con – Lifetime Costs
Cars provide a useful pricing analogy. A new vehicle is a hefty upfront cost. The convenience of one low monthly lease payment looks great at the beginning. But when the lease is up and you owe hundreds for mileage overage and then have to pay an exorbitant amount to keep the car, the lifetime costs hit home. It can sometimes be the same with public cloud storage. Once you tally up the costs over three, four or five years will it really be cheaper than on premise? For some, the answer will be no.
“Your costs over time might increase,” said Schulz. “If your applications are local yet your data is in the cloud, it can add to networking costs and result in increased latency.”
Cons – Security
Handing data off to a public cloud provider poses security and privacy concerns. Breaches across almost every public cloud service continue to be regularly reported by the media A survey that Nexsan conducted revealed that only about 3 percent of respondents felt that sharing files outside of the office was private and secure.
“Never store anything sensitive in the public cloud,” said Watson.
Dave Ginsburg, CMO at Teridion emphasized additional areas of public cloud security worry, such as managing permissions (both internal and external), vendors accessing your files for marketing and encryption purposes, confidentiality of intellectual property, transfers when on WiFi, synchronization (which document is accurate and are any incorrectly overwritten?), multiple public cloud providers, accidental deletion on shared drives and lack of clear-cut audit trails.
Con – Speed
Another potential downside of public cloud storage is download and data speeds (i.e., bandwidth). Despite the fact that cloud storage has achieved some good results on benchmark tests, 22 percent of respondents to the Nexsan survey reported that the main barrier to public cloud storage was the time it took to download and upload files.
Con – Compliance
In some heavily regulated industries, it is just too unworkable to use the public cloud. Healthcare, financial services and publicly traded companies have to tread very carefully if considering the public cloud.
“Regulatory compliance can be tricky with these public cloud solutions and requires careful attention,” said Watson. “This can become an even bigger issue if a third party and numerous jurisdictions have possession of the storage/data.”
Con – Noisy Neighbors
Noisy neighbors are a big concern of IT managers. One cloud application or one user with high IO traffic impacts the performance of another user.
“Where possible, IT managers should look for cloud storage providers who provide resource isolation to avoid co-mingling with other data,” said Liebl.
|Offsite management||Lifetime costs|
|Speed (backup)||Speed (DL and data transfer)|
|Lower upfront cost|