storage is arguably the most important decision you will make regarding a server. the base function of many servers is as a networked attached storage (NAS) device, which is a fancy way of saying: a place to keep all your stuff. think of it as a digital storage unit for everything cluttering up your local hard drive. the NAS’s job is to act as a central repository to keep everything as well as give you access to it from your local network, or possibly the entire internet. as such, the hard drives all that data resides on are as precious as what is stored on them.
when deciding on hard drives, the most important factor isn’t actually size, but how the data is physically written to the disk by the magnetic head. without getting too technical, the data is written either with a “buffer” on both sides (CMR) or overlapping (SMR). for servers that do long writes (think backing up your hard drive) that buffer slows things way down and can sometimes break the writing process. as such, any hard drives that go into servers need to be CMR only! here is an illustration to visualize the differences:
there are some favorites among the enterprise community that rise to the top of the CMR stack. these are the drives you should look for when choosing from the myriad of selection offered by the internet:
- Western Digital Red Pro
- Western Digital Red Plus
- Seagate Ironwolf
- Seagate Ironwolf Pro
- Seagate Exos
all of these drives are CMR and rated to withstand the pounding typical NAS’s deliver to them 24/7. the difference between the more affordable WD Red Plus to RED Pro or Ironwolf to Ironwolf Pro, is usually length of warranty and the maximum speed at which the drives spin. the drive speed is no big deal and makes negligible difference, but the warranty is nothing to sneeze at. if you are a person who expects to put your server through the ringer, it may be something to consider when selecting drives.
lastly, price. new drives usually priced between $15-20 per terabyte (TB). anything under $15/TB is considered very cheap and if you see a deal like this jump on it. in the used market $10/TB is the going rate. newer drives still under warranty can go for more, but the closer you get to that $15, the worse deal you are getting since a sale usually occurs every month. as a side note, there is nothing wrong with buying used drives as long as the power-on hours are still on the low side. this video done by Linus does a great job explaining somethings to look for when shopping for used drives.
there will be separate posts about which RAID to choose and what size your hard drives should be for your use-case. this is just a primer of the basics of the hardware so you can make an informed choice when scrolling through amazon, newegg, or ebay. happy hunting!