We’re not going to point any fingers, but a cursory scan of IT industry news describes increasing numbers of hard drive failures and infractions caused by unreliable drives at cloud organisations, including web hosting companies.
Many hosts offer large amounts of cheap HDD (Hard Disk Drive) space but is the old adage true, that you get what you pay for? Yes. Tests have shown that HDDs have a failure rate of between 2 and 5% compared to SSDs (Solid State Drives) with an average failure rate of .05%. Not very reassuring odds if you’re running a business. Just as importantly, the superior performance of SSDs is pretty much unquestionable, up to 1000 times the number of I/Os (read/ write speed) per second compared to HDDs.
Again, what kind of performance are your customers expecting from you? The truth is that cost is the only driving factor for using HDD drives for hosting, so, yes, you get what you pay for.
Let’s take a look at the differences between SSDs and HDDs and some insight into why you pay a bit more for SSD hosting.
Acronyms and definitions
SSDs and HDDs - What is the difference between a Solid State Drive (SSD) and a Hard Disk Drive (HDD)? The short answer is that SSDs are faster, more reliable and, although the initial outlay for them is more, they last longer. An SDD can be compared to a memory stick; it has no moving parts, unlike an HDD which has a mechanical arm it uses to access and write information, a bit like old vinyl records. However, HDDs are a lot cheaper than SDDs and are recommended for anyone who wants loads of space without having to spend too much. Data is stored on an SSD on microchips; it works in a similar fashion to a smartphone or other mobile device. SSDs are very fast and even though they too eventually wear out, their life expectancy is far longer.
SATA - You’ll hear the term SATA bandied around a bit when you research drives. Serial AT Attachment is a technology that connects your computer to a mass storage device, like an SSD or HDD.
Non-volatile memory - SSDs use non-volatile memory to store information which means data is not lost when power is disconnected. Non-volatile memory is different to traditional volatile memory (RAM) which, if the power is cut off, disappears into the ether forever.
RAID - is another acronym you need to understand. Redundant Array of Independent Disks describes the scenario where two or more drives work together to enhance performance or redundancy. Two drives work together as one drive, faster and more efficiently because there are twice as many resources available during read/ write operations. More importantly, if one drive dies, the other takes over, taking effect much as a generator does when your electricity gives up the ghost.
Localnode uses RAID 10 with Fastpath. A RAID 10 configuration requires a minimum of four discs and stripes data across mirrored pairs. As long as one drive in each mirrored pair is functional, data can be retrieved. It’s more expensive for a host to implement because data is duplicated (mirrored), so, effectively, your host needs to buy twice as much disc space. Again, you get what you pay for.
Note: RAID is not a substitute for proper backups. RAID is designed for redundancy so that data remains usable when a drive fails. You need a backup system so that if you want to go back and retrieve data you accidentally deleted or return to a previous version of your work, you can. At Localnode we use R1Soft and Amazon S3 for backups, for more information on our backups read this blog post.
Fastpath - This is a nifty mechanism whereby responses to incoming network traffic are sent back using the same interface as the incoming traffic. A fast path can handle the most commonly occurring tasks with a “normal” path handling other tasks. Think of it as a special lane on a highway, reserved for school buses, the mail carrier, etc., with the “normal” lane reserved for emergency vehicles.
What’s so great about SSDs?Less noise – They’re quieter than HDDs, which is essential for quality sound enthusiasts.
Faster – HDDs can suffer from fragmentation, a situation where the data required is not readily available in one contiguous block. The drive, therefore, needs to make multiple physical accesses for data (this seldom occurs in Linux). With SSDs, data can be stored anywhere on the device so it’s inherently faster. Also, backup rates are faster and CPU idle times shorter for SSDs.
Reliability – SSDs are more durable. You may have noticed that dropping your phone effects little damage other than cracking the screen; the device still works. Try that with a hard drive.
Smaller – SSDs are smaller. HDDs require a lot more physical space so their future is assuredly not in the personal mobile device market.
Energy conservation – SDDs produce less heat energy and thus use up a little power for cooling purposes.
Do you really need it?
HDDs and SSDs are aimed at different markets. If you need a lot of space, for instance, to store videos and other multimedia like games and you’re on a budget, HDDs are the way to go. But they’re not what you expect from a high-tech web host.
When it comes to choosing a web host that uses HDDs and one that uses SDDs, it’s a no-brainer. There are two main issues that affect customers (cost, durability, longevity, etc. are arguably the host’s concern).
Speed – The faster your clients can access data on your site, the better. Fast performance makes for happy visitors.
- Today’s internet users demand speed. The days of waiting for a page to load went the way of paying an ISP to host your email account.
- SSDs perform consistently better because of the way they are designed to operate and because there’s less chance of fragmentation which slowly but insidiously can debilitate an HDD.
- Because of RAID, SSDs can handle a sudden influx of visitors to your sites as two or more drives are able to share the effort required to serve them.
Reliability – Data integrity is essential to any business. Resorting to excuses for losing customer data “because the system went down” doesn’t wash since the advent of SSDs.
- RAID ensures that if one drive dies, the other can continue working; you wouldn’t fly in a plane with only one engine, no matter how powerful that engine, would you?
- The use of non-volatile memory to store information means that data is not lost when power is disconnected. If you’re running an e-Commerce site or storing visitor’s passwords and personal information, you can’t afford to trust the vagaries of the electricity grid in a storm.
There is a difference between cheap and affordable web hosting.
Mechanisms like Fastpath ensure efficient data access by enabling intelligent data routing. At the risk of flogging a dead horse, consider the roads you drive on each day to work. They’ve been planned; you don’t just point your car at the nearest gap in the general direction you’re going.
SSDs are becoming cheaper as most technologies do. For sure, store your music and movies on HDDs at home but there’s really no excuse for your web hosting company still to be using HDDs.