So, here are teenager servers, what can we expect of them? Are they any good?
If you happen to buy some used servers you probably end up buying hardware that is about 10-15 years old. Anything older is usually seriously deprecated. When servers reach the ripe old age of 15-20 they are usually like old-timers in the car world. They are fun, they are nice, they are sure a great hobby, but they are not running that fast and there is a lot of maintenance involved.
So what can we expect from a 10-15 years old servers? Are these provide any value at all? Can they be seriously used, run for a real job? Well, let's see. Let's check on the disks first. Let's see what can we expect of the teenager servers from the storage point of view.
First, it is important to understand that servers are usually strong in the storage department, relatively stronger than desktops and laptops. Yes, compared to the PC the CPU in an enterprise server is more serious, the memory is better, but the difference between a server storage and a desktop storage is usually bigger. Yes, 10 years are 10 years, but still, an enterprise server is an enterprise server.
These servers, practically all of them have SAS drives, not SATA. SAS is similar to SATA, but it is is better. SATA drives are running on 7200 RPM or 5400 RPM while SAS drives are usually 10K or 15K. They might be spinning 3 times faster than the drive you used to. They also seem to have a better quality. I might be wrong, it is just a feeling, but they feel to be better. So the second thing is that server SAS drives are faster and more reliable.
The servers have SAS RAID cards, they are usually compatible with SATA too, you simple plug the SATA drive in and it works. You usually can't mix the SAS and SATA drives in one virtual disks, but you can mix them in one server, no problem there. SATA drives might be even cheaper to buy, especially the big ones so we might want to be open-minded about SATA too.
The third thing is the RAID card. All the servers have proper RAID cards and that is a big plus on their side. Handling a storage with a proper RAID card is a huge difference not just for the fault tolerance, but for the reliability and the speed too. When 6, 8 or even more disks are running together they are indeed more than the sum of the parts. Yes, there is the software RAID, but that's a joke, and yes, there are RAID cards in some other computers too, but the proper server RAID card is included in the enterprise servers and that's great news!
The fourth thing to remember is the hot-swappable disks. Replacing a disk while the server is running is not that important in a home IT system, sure, but hot-swap also means easy access. To install or replace a disk in a desktop might take half an hour, even more. You need to disconnect, mine the box from under the desktop, open it up, cables, screws... then you realize you don't have the cable, not enough power connectors... it is a very annoying work that you may have to do from time to time. Installing or replacing a disk may be as fast as 5 seconds when you are dealing with a server.
But really, there is a yellow light blinking, you notice it, you open the box of replacement disks, pick one out, left hand removes the old disk, right hand installs the new disk, wait for a few seconds, it is blinking. The RAID card already started to rebuild the data, let's have a coffee. Takes more time to write it down than doing it, you just need to keep some extra disks near your server.
And let's not forget that sometimes you want to move disks around even if the disks are not failing. You may want to install some extra storage check a disk that you bought, maybe archive something or whatever. Hot-swap disks are the best since sliced bread for sure!
And of course the money. If you don't need huge storage the price of the second hand 3,5" SAS disks is pretty low. You can buy 72, 146 GByte disks for next to nothing, especially if you buy it bulk. Buy them with caddies, buy a bunch of them, they are very reliable, you won't regret it. Yes, huge disks like 2TB, 6TB, those might fail, you need to be careful buying those. Also 2.5" disks might be a high risk, better not buying them second hand at all. But the smaller capacity 3.5" disks are great. You put 3-6 72-146.300GByte disks into your server and they will not fail you... well, especially when you use a redundant RAID version. Disks without redundancy is like playing Russian roulette with a glock, you loose the first time you have a chance.
And even if one goes wrong what's the harm? For a price of a cheeseburger and a large coke you put in the replacement in under 15 seconds.
And of course I also have some bad experience, some things that I learned for a price... that I had to pay.
First, I do not buy second hand 2.5" disks. Multiple sources sent me many faulty drives of these, a lot of wasted time and money. I could try to get the money back, sometimes I do, but not always. Sometimes the disk fail after a few months, sometimes you don't even test them for weeks, sometimes I am just too lazy to send them back. Anyway, 2,5" disks have smaller area holding the same amount of data or something else... dunno, don't care. I am not buying them any more.
The other thing is that I never buy SSD second hand. Not ever. If that SSD was removed from a computer it was removed for a reason. Because it is broken, that's why.
And even when you buy a new disk you still might buy a used one, even one that was used for many-many years. Even if it looks like having the original packaging. Even if the SMART info says it is new. Sellers sometimes say the disk is refurbished, which is impossible, of course. Sometimes they say they checked it. Well, they don't. They delete the data from it, yes, that's true.
And by the way, this whole article sounds like a set of advises, here is one that really is and advice, really is important. Here is the best advice I heard in my life: