Only one good answer : SSD :smart:
There is no reason today to use hard disk as they are slower, less secure and only few dollars cheapers than SSD. There are already dedicated servers with 4x 500GB SSD for the same price than a 2x 2TB HDD server. And if you really need to store a huge amount of data, there are cloud services like Amazon AWS.
The only risk of loosing data with a SSD is if you store it during a long time without power. This will never happen in web hosting ^^
I use SSD on all servers - except on the servers I use for storing backups, which use mechanical drives.
As the backup data isn't being accessed as much (if at all) it's fine (IMO) to use mechanical drives.
SSD's are ultimately more reliable, much better performance, and environmentally friendly.
Nothing is infallible - SSD's can fail, too.
This review is a bit more driven to SSD vs HDD for laptop's not web hosting so keep that in mind
Here is a snippet
Most people now buy laptops for their computing needs and have to make the decision between getting either a Solid State Drive (SSD) or Hard Disk Drive (HDD) as the storage component. So which of the two is the better choice, an SSD or HDD? There's no straight-forward answer to this question; each buyer has different needs and you have to evaluate the decision based on those needs, your preferences, and of course budget. Even though the price of SSDs has been falling, the price per gigabyte advantage is still strongly with HDDs. Yet, if performance and fast bootup is your primary consideration and money is secondary, then SSD is the way to go. For the remainder of this article, we will make a comparison of SSD and HDD storage and go over the good, the bad, and the ugly of both.
What is an SSD?
We'll make no assumptions here and keep this article on a level that anyone can understand. You might be shopping for a computer and simply wondering what the heck SSD actually means? To begin, SSD stands for Solid State Drive. You're probably familiar with USB memory sticks - SSD can be thought of as an oversized and more sophisticated version of the humble USB memory stick. Like a memory stick, there are no moving parts to an SSD. Rather, information is stored in microchips. Conversely, a hard disk drive uses a mechanical arm with a read/write head to move around and read information from the right location on a storage platter. This difference is what makes SSD so much faster. As an analogy, what's quicker? Having to walk across the room to retrieve a book to get information or simply magically having that book open in front of you when you need it? That's how an HDD compares to an SSD; it simply requires more physical labor (mechanical movement) to get information.
A typical SSD uses what is called NAND-based flash memory. This is a non-volatile type of memory. What does non-volatile mean you ask? The simple answer is that you can turn off the disk and it won't forgetâ€ what was stored on it. This is of course an essential characteristic of any type of permanent memory. During the early days of SSD, rumors floated around saying stored data would wear off and be lost after only a few years. Regardless, that rumor is certainly not true with today's technology, as you can read and write to an SSD all day long and the data storage integrity will be maintained for well over 200 years. In other words, the data storage life of an SSD can outlive you!
SSD is highly recommended, it has much better performance with much less maintenance needs.
In regards to loosing data; most reseller plans include daily backups which should avoid that being an issue. (e.g. R1Soft)
At the time of the SSD 2016 is the preferred choice for your computer . Because it has a higher life expectancy than SATA HDD and read speed read / write much faster . And above all it is very compact . You can choose to install a Windows HDD . Contains the data you choose HDD
RAID is not used anymore if VPS are running on a cloud platform like OpenStack. Ceph storage provide triple replication with good performances.
Using NVMe Drive (SSD with PCI-Express connection) SSD are now the only choice for web hosting, HDD should be use only for storage purpose.
Something I haven't heard mentioned is that SSD's wear out at some point just like mechanical drives. SSD's can only be written to so many times before failing. Although these writes would need to far exceed the size of drive by probably hundreds of times, I think it is worth noting SSD's are not invincible.