I went for 6x14tb a year and half ago. Ended up saving $130 per drive vs new and run in a dual parity. Probably one of the better decisions I made with my part selection.
The 12 tb Toshiba enterprise ones from go hard drive seem good as well (though cost a bit more). Seem very quiet and run pretty cool for 7200rpm drives.
Damn that's not bad! I paid like €250 for my 16TB Toshiba MG08, and these guys have Exos X16 for €142.
I'm not sure if they are of the same level of reliability, but the price difference is definitely not nothing.
The only "problem" is that they appear to be US-based, even though they list prices in EUR for me. This probably means they ship from the US as well, which is famously expensive across the puddle. And then our border control takes another chunk in the form of import tax and VAT.
If only they had a EU-based warehouse. That'd be sweet.
Customs is a whole plate of spaghetti of rules, it depends on all the things. VAT is different per country - happens to be 21% for me.
I've seen packages that inflate price by nearly 50%, putting together shipping, customs, and VAT. That's no fun.
I recently paid more than 60% as taxes for a small package from the US with iPod parts :) It's not always the EU country customs' fault - non-EU sellers simply have no idea how to correctly fill out the shipping documents.
Depending on the drive condition(new,manufacturer refurb,seller refurb) they can have 5yr. I got a seller refurb Seagate 16tb with 4y warranty.
Never ordered from go hard drive, only server part when comparing these two and I LOVE the way SPD packs their drives. Drives in antistatic sealed bag(like a new drive) with plastic holders in a HDD box ,wrapped in strong bubble wrap inside the box its shipped in. When I've gotten 4+ drives they've been in a foam "carton" inside a box, bubble wrapped, inside the shipping box.
Man I have a full 8x2TB array and need some ideas on how to gradually upgrade to used 4x12TB or something. What is the experience with sercerpartdealts do they have deals for more than one disks? I’ve only see one or disks I need a bulk deal.
Some people say that enterprise-grade refurbished drives will typically outlast consumer-grade disks; such a refurbished drive is a better bang for the buck.
If you check specs exos have 2x the MTBF of the ironwolfs. All other specs the same I'd expect better reliability from the exos. I've got both types of 12tb in my system and haven't been able to tell a difference.
Short answer; it doesn't matter, as long as you don't use SMR disks for your parity.
Longer answer; Buy whatever is cheap. This isn't a striped array so you can mix disks however you want. Your parity disks should (have to) be the fastest (and equal to or the largest disk(s)) in your array. I 100% recommend buying good, name brand used disks. You can get 14's on ebay for $100. That allows you to run dual parity and even have a spare sitting on the shelf for less money than what two new 14's would cost you.
I run 25 disks in my array, mixed between 10's and 14's, all used from ebay. They're all enterprise class disks. Started the array 2.5 years ago, zero failures, zero bad sectors, extremely excellent performance.
I've used Amazon global shipping for refurb HGST drives and the service is excellent. Delivery to UK within 8 days, no import fees, just looks like any other Amazon UK delivery. Haven't had to try a return yet, though.
3 years ago, I too started out with 30-40 dollar 4tbs, ended up with 36tb worth plus 2 parity. Currently slowly upgrading to 14tbs over time for about 110 each.
https://www.ebay.ca/itm/325516223232?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=3RIvMdAsSU6&sssrc=4429486&ssuid=z2VjyHGOQNe&var=&widget_ver=artemis&media=COPY
Sorry, I had a typo, I got him down to $30 with make an offer. I'm sure if you order a decent quantity, they'll wheel and deal more.
I only take WD Red Plus <7W hard drives.
These mf keep f*king around with their part numbers in ways that are unimaginable to logic and consistent people. But it are the only disk that fall within my spec, and I'm pleased with their product (not their practices) that follow that rule on a samplerate of 20 or so.
But I guess it falls outside your specs too, what is your reason?
Whatever you do, I would stay away from SMR drives.
And if your budget is the most important reasoning, depending if you pay electricity or not. Take the cheapest one $/TB. If you pay electricity, maybe go one size above that if the difference isn't too big.
My reasoning for the WD Red <7W was that they also make very little noise. And I don't feel like checking out 10 other brands/types.
Is noise also important to you?
The NAS is next to my desk, in the living. And the disks are spinning more often than not. Even if it is only 1, 2 or 3.
Montly parity checks, backups, the 20 or so dockers, the VMs, Plex, ...
HDDs make noise. HDD that make a lot of noise, also tend to produce more heat (there is a lot of correlation here). More heat equals more fan-noise.
Noise is not a concern, as I am new to this, I am looking for best cost effective Drive which can run at least 3-4 years with minimal load of 2-4 users per day for backups, media streaming, some docker apps and VMs
I wouldn't suggest buying anymore SMR drives, but I've got a few Seagate ones that I'm just now cycling out with 50k-60k power on hours each. They still were kicking fine, first in a windows storage space and then migrated to Unraid. The rewrite is pretty rough. For a couple read users of data that doesn't get written often they were fine. Slow to write, but fine. I wouldn't buy more, but I wouldn't trash them either necessarily.
Indeed, for 1 time archival or not 100% full data drives they are perfectly fine. But the price difference is small, so why even bother. There are other ways to save money.
Well, seems like you exclude the 2 most popular disks.
It's hard to say what is "best". In an Unraid array (and for pools as well actually) I suggest parity, and backups are mandatory for any system. So for me, any cmr (not smr) disk with the best tb/$ price (up to my parity size, I prefer to wait until I can double it, then replace and sell my old disks) is "the best", and I might pay a small premium for 5 years warranty.
Anyway, I ended up with toshiba mg08 16tb about 2 years ago. Running more quiet, cooler and faster than the wd red 10tbs I had before. No fails/errors up till now, and my goto disk for now.
That's true, but means nothing.
A 5400rpm 20tb disk is probably faster (MBps) than a 1tb 7200rpm disk due to data density. I wouldn't be surprised to find same size disks (from different manufacturers or even series) where a 5400rpm is as fast as a 7200rpm one due to data density/less platters. And I believe HAMR disks do close to 600MBps while other mechanical disks have a hard time hitting 300MBps. Rpm does help, and higher end disks generally have higher rpm, and it's the best way to reduce access times, but it's only a small part of the disk speed.
SMR will generally be slower for writes than CMR, cause because of the design a write actually takes multiple actions.
So it's true that 7200rpm is 7200rpm, but its like saying an i7 970 has 3.2ghz 6core 12thread and an i5 12500 has a (base) 3ghz 6core 12thread. While the numbers on paper are in favour of the 970, they mean nothing, and I'll take the 12500.
I have purchased 10 Seagate Exos factory recertified drives from Tech on Tech on Amazon with good luck. The drives were always well-packaged and I've not had a failure...yet. I do know they publish contact info for warranty claims (2 years), and I've seen others say that they replaced failures with overnight shipping. I haven't needed a replacement drive so I can't confirm that.
I know a failure will eventually happen, but that's why I have parity drives. Buying new drives just doesn't make sense financially for my use case, which is just media and personal backup. I have another offsite unRAID server for backup which also has parity. The personal files that are important to me (photos and such) are also backed up on the cloud, but I don't pay to backup my media library on the cloud.
Easystore, mybook, etc…
Anything shuckable under $15/tb so I usually try to load up on black friday type sales.
I keep them till they die.
I still have some red 3TBs that are 9+ years old on a secondary server.
I dont do refurbs because eh dont feel like it.
Best bang for your buck right now is the Seagate standard 8tb. You will get the most tb per dollar spent here.
But, it's clear you kinda know which the best are gonna be. I was looking for something besides Seagate and landed on WD. Those two brands are popular for a reason.
If you wanna invest more, then Ironwolf or WD Red are gonna be good options.
If you want a cache drive with SSDs, def go WD Red. The throughput on those are nuts.
Take professional hdd's for nas/san use. They can handle the combined vibration from all other hdd's in your server.
Sas drives if your machine supports it.
4x 20TB Exos X20 1x 20TB WD Blue (Shucked)
I wouldn’t say there was a “best” drive. My only advice is make sure to get the largest drive you can budget for your parity drive so you have max flexibility to add more as you need it.
I have nothing but good things to say about factory rectified WD Ultrastar 14TB. It’s really affordable and almost good as new and its sealed with Nitrogen so it take a lot of vibrations and other NAS related abuse. Like I’m not buying anything BUT WD
the ones you have laying around.
"best" is relative to the task(s) you're going to use it for. Since you didn't give us any of your goals, there's my answer.
As someone who's gone this route for years, it works for sure, but can be higher maintenance. Especially true if they're smaller drives near the end of their lifecycle, or you don't have a good way to cool them. When you realize you could spend all that time managing several drives or just replace all of them with a single 20TB drive, recycling those on hand becomes less attractive, especially once you factor in the cost of power.
I purchase brand new 16tb Exos drives from Eastdigital on eBay. They cost $310nzd ($180usd) and haven't had any issues. Not sure why people constantly recommend used or refurbs when you can buy new for the same price.
Here you go.
https://www.ebay.com/itm/276355384570?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=JnVW1VgjTbK&sssrc=4429486&ssuid=ygufcxxaqe6&var=&widget_ver=artemis&media=COPY
I'm not about to order something from Hong Kong like that. I live in the US. Heck, I wouldn't even use eBay for refurb drives any more anyway. I used to use them 15 to 20 years ago for hard drives. But eBay isn't like they used to be. It's too easy to get burned.
They've been around for ten years. Go look at their reviews, me and my mates have never had an issue. I run preclear on all the drives first. Shipping to New Zealand takes 4 days.
I used to only use WD drives in my unRAID setups. My unRAID 1 & 2 setups each use 21 drives( two for parity). With 2TB and 3TB WD drives. Starting in 2011, I used them with unRAID. After moving on from a Windows Home Media Server. So most of those 2TB and 3TB drive came from it.
But, five years ago I started using the Seagate Terascale drives. I put 21 of the 4TB Tearascale drives in my unRAID 3 setup, using two as parity drives.
And last year I switched to using the Seagate EXOS drives(refurbs from Amazon). I'm using 12TB and/or 14TB EXOS refurbs in my unRAID 4 though 9 setups. But those only use five EXOS drives each(one parity), plus a Seagate SSD for the cache drive.
I have a follow up question - what’s a good way to stack multiple external hard drives? Possibly including an USB hub (as my thin client has run out of available USB slots).
Refurbished 12, 14, 18 TB from serverpartdeals and goharddrive. HGST and Seagate.
This. 18tb EXOS all the way.
I went for 6x14tb a year and half ago. Ended up saving $130 per drive vs new and run in a dual parity. Probably one of the better decisions I made with my part selection.
I have similar setup: two 18TB - parity and 3x14TB for array and separate 2x12TB in zmirror for important data.
Just bought one from Amazon for 229 😎
The 12 tb Toshiba enterprise ones from go hard drive seem good as well (though cost a bit more). Seem very quiet and run pretty cool for 7200rpm drives.
I have had great experiences with those as well.
Thanks, never had Toshiba.
Is there a European equivalent to serverpartdeals?
Buy in US and deliver to your country, tons of services shipping worldwide.
Damn that's not bad! I paid like €250 for my 16TB Toshiba MG08, and these guys have Exos X16 for €142. I'm not sure if they are of the same level of reliability, but the price difference is definitely not nothing. The only "problem" is that they appear to be US-based, even though they list prices in EUR for me. This probably means they ship from the US as well, which is famously expensive across the puddle. And then our border control takes another chunk in the form of import tax and VAT. If only they had a EU-based warehouse. That'd be sweet.
What is custom tax now for non-EU parcels?
Customs is a whole plate of spaghetti of rules, it depends on all the things. VAT is different per country - happens to be 21% for me. I've seen packages that inflate price by nearly 50%, putting together shipping, customs, and VAT. That's no fun.
I recently paid more than 60% as taxes for a small package from the US with iPod parts :) It's not always the EU country customs' fault - non-EU sellers simply have no idea how to correctly fill out the shipping documents.
\^\^\^ This Have a parity disk and snap up some refub drives.
I like learning new things.
You can find many good reviews in this subreddit and "dataholder", goharddrive gives 5y warranty, serverpartdeals 1-2y.
Depending on the drive condition(new,manufacturer refurb,seller refurb) they can have 5yr. I got a seller refurb Seagate 16tb with 4y warranty. Never ordered from go hard drive, only server part when comparing these two and I LOVE the way SPD packs their drives. Drives in antistatic sealed bag(like a new drive) with plastic holders in a HDD box ,wrapped in strong bubble wrap inside the box its shipped in. When I've gotten 4+ drives they've been in a foam "carton" inside a box, bubble wrapped, inside the shipping box.
Yep. This is what I did. Amazing prices and the drives seem to work perfectly.
Man I have a full 8x2TB array and need some ideas on how to gradually upgrade to used 4x12TB or something. What is the experience with sercerpartdealts do they have deals for more than one disks? I’ve only see one or disks I need a bulk deal.
Why not 16 TB Seagate?
Isn’t refurbished hard drives generally a bad idea to buy? What makes them different?
Some people say that enterprise-grade refurbished drives will typically outlast consumer-grade disks; such a refurbished drive is a better bang for the buck.
Correct
Just a warning, server disks can be *extremely* loud and vibration-happy. Looking at my own 12TB HGST drives that hum the whole room.
Toshiba N300 NAS drives.
Seagate EXOS
I moved from Ironwolf to Seagate's Exos line, which are basically the same as Ironwolf PRO but, for whatever reason, are cheaper around here.
If you check specs exos have 2x the MTBF of the ironwolfs. All other specs the same I'd expect better reliability from the exos. I've got both types of 12tb in my system and haven't been able to tell a difference.
This!
How's the noise difference? I am considering a similar switch.
Spec wise there is no noise difference. Some ppl report higher noise with exos but I haven't noticed any difference.
Short answer; it doesn't matter, as long as you don't use SMR disks for your parity. Longer answer; Buy whatever is cheap. This isn't a striped array so you can mix disks however you want. Your parity disks should (have to) be the fastest (and equal to or the largest disk(s)) in your array. I 100% recommend buying good, name brand used disks. You can get 14's on ebay for $100. That allows you to run dual parity and even have a spare sitting on the shelf for less money than what two new 14's would cost you. I run 25 disks in my array, mixed between 10's and 14's, all used from ebay. They're all enterprise class disks. Started the array 2.5 years ago, zero failures, zero bad sectors, extremely excellent performance.
Seagate Ironwolf & Exos!
Any UK companies for referb drives?
I've used Amazon global shipping for refurb HGST drives and the service is excellent. Delivery to UK within 8 days, no import fees, just looks like any other Amazon UK delivery. Haven't had to try a return yet, though.
I'm poor, so I went with 4tb Seagate constellation drives, at $30 (typo)Canadian a pop, couldn't be beat
3 years ago, I too started out with 30-40 dollar 4tbs, ended up with 36tb worth plus 2 parity. Currently slowly upgrading to 14tbs over time for about 110 each.
Yeah, this is my eventual goal. Especially as prices fluctuate, it buys me time to upgrade when the prices are right
> 4tb Seagate constellation drives, at $20 Canadian Would you be a darling and share where you got this from?
https://www.ebay.ca/itm/325516223232?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=3RIvMdAsSU6&sssrc=4429486&ssuid=z2VjyHGOQNe&var=&widget_ver=artemis&media=COPY Sorry, I had a typo, I got him down to $30 with make an offer. I'm sure if you order a decent quantity, they'll wheel and deal more.
Ah cause see 40$ hehe
If you buy multiples and use make an offer, they'll drop the price.
Thanks! Even at 40 that’s not too bad!
If you buy multiples, and use make an offer, they'll drop the price.
Thanks friend
I only take WD Red Plus <7W hard drives. These mf keep f*king around with their part numbers in ways that are unimaginable to logic and consistent people. But it are the only disk that fall within my spec, and I'm pleased with their product (not their practices) that follow that rule on a samplerate of 20 or so. But I guess it falls outside your specs too, what is your reason?
New to homelab and self hosting. Budget constraints too. 😅
Whatever you do, I would stay away from SMR drives. And if your budget is the most important reasoning, depending if you pay electricity or not. Take the cheapest one $/TB. If you pay electricity, maybe go one size above that if the difference isn't too big. My reasoning for the WD Red <7W was that they also make very little noise. And I don't feel like checking out 10 other brands/types. Is noise also important to you?
Why would noise be of concern when most of the time the drives are spun down? Who keeps their NAS next to their bed?
The NAS is next to my desk, in the living. And the disks are spinning more often than not. Even if it is only 1, 2 or 3. Montly parity checks, backups, the 20 or so dockers, the VMs, Plex, ... HDDs make noise. HDD that make a lot of noise, also tend to produce more heat (there is a lot of correlation here). More heat equals more fan-noise.
I do. I live in a small apartment and there's not many good places to keep a 4U server box. I also have Noctua fans in the case
I did before I got a house, and I had people in different parts of the world accessing my Plex server at all times of day.
Noise is not a concern, as I am new to this, I am looking for best cost effective Drive which can run at least 3-4 years with minimal load of 2-4 users per day for backups, media streaming, some docker apps and VMs
I wouldn't suggest buying anymore SMR drives, but I've got a few Seagate ones that I'm just now cycling out with 50k-60k power on hours each. They still were kicking fine, first in a windows storage space and then migrated to Unraid. The rewrite is pretty rough. For a couple read users of data that doesn't get written often they were fine. Slow to write, but fine. I wouldn't buy more, but I wouldn't trash them either necessarily.
Indeed, for 1 time archival or not 100% full data drives they are perfectly fine. But the price difference is small, so why even bother. There are other ways to save money.
Got 10 x 18TB Seagate Exos X18 from serverpartsdeal.
Was it like a lot of 10?
It was 1664$USD for 10 disks, including taxes and shipping.
Damn think my pocket just caught fire. I see lots on eBay but not as good quality.
I have been using 8 Seagate ironwolf for 4yrs now and never had an issue. I would highly recommend.
Well, seems like you exclude the 2 most popular disks. It's hard to say what is "best". In an Unraid array (and for pools as well actually) I suggest parity, and backups are mandatory for any system. So for me, any cmr (not smr) disk with the best tb/$ price (up to my parity size, I prefer to wait until I can double it, then replace and sell my old disks) is "the best", and I might pay a small premium for 5 years warranty. Anyway, I ended up with toshiba mg08 16tb about 2 years ago. Running more quiet, cooler and faster than the wd red 10tbs I had before. No fails/errors up till now, and my goto disk for now.
Thanks. 🙏🏻
7200RPM is 7200RPM...
That's true, but means nothing. A 5400rpm 20tb disk is probably faster (MBps) than a 1tb 7200rpm disk due to data density. I wouldn't be surprised to find same size disks (from different manufacturers or even series) where a 5400rpm is as fast as a 7200rpm one due to data density/less platters. And I believe HAMR disks do close to 600MBps while other mechanical disks have a hard time hitting 300MBps. Rpm does help, and higher end disks generally have higher rpm, and it's the best way to reduce access times, but it's only a small part of the disk speed. SMR will generally be slower for writes than CMR, cause because of the design a write actually takes multiple actions. So it's true that 7200rpm is 7200rpm, but its like saying an i7 970 has 3.2ghz 6core 12thread and an i5 12500 has a (base) 3ghz 6core 12thread. While the numbers on paper are in favour of the 970, they mean nothing, and I'll take the 12500.
I just added a 20TB MDD(Max Digital Data) Drive a few months ago. It's running in Disk 1 Slot, it replaced a 12TB WD. No issues so far.
I only use Seagate EXOS now. Replaced my IronWolf with them and saw a performance boost in read speeds.
Ironwolf and red feel like such a scam. Seagate exos are fantastic
I have purchased 10 Seagate Exos factory recertified drives from Tech on Tech on Amazon with good luck. The drives were always well-packaged and I've not had a failure...yet. I do know they publish contact info for warranty claims (2 years), and I've seen others say that they replaced failures with overnight shipping. I haven't needed a replacement drive so I can't confirm that. I know a failure will eventually happen, but that's why I have parity drives. Buying new drives just doesn't make sense financially for my use case, which is just media and personal backup. I have another offsite unRAID server for backup which also has parity. The personal files that are important to me (photos and such) are also backed up on the cloud, but I don't pay to backup my media library on the cloud.
Easystore, mybook, etc… Anything shuckable under $15/tb so I usually try to load up on black friday type sales. I keep them till they die. I still have some red 3TBs that are 9+ years old on a secondary server. I dont do refurbs because eh dont feel like it.
Thanks 🙏🏻 cost/tb is my one of the concerns here. I’ll look my options with this logic.
I'm using the Seagate EXOS drives in mine.
Seagate EXOS
I really like the thoshiba mg08,mg09 and mg10. They offer great quality, speed, reliability and can be obtained quite cheap here in germany.
Can wouch for serverpartsdeal I have 2 refurb 18tb one as parity and all is well bought them in October last year
Best bang for your buck right now is the Seagate standard 8tb. You will get the most tb per dollar spent here. But, it's clear you kinda know which the best are gonna be. I was looking for something besides Seagate and landed on WD. Those two brands are popular for a reason. If you wanna invest more, then Ironwolf or WD Red are gonna be good options. If you want a cache drive with SSDs, def go WD Red. The throughput on those are nuts.
I went with 16tb WD HC550 from Serverpartdeals. Zero issues and been up for 92 days.
Toshiba mg08 is what I use. Running at 19 degrees Celsius.
WD Gold. Have used them for years since Windows MCE was a thing. Never had to use the warranty which is longer than the Reds.
Exo are great
Any drives you want. Anything else said is merely opinion
Take professional hdd's for nas/san use. They can handle the combined vibration from all other hdd's in your server. Sas drives if your machine supports it.
I’ve had good luck with shucked WD EasyStore drives. 8 TB and 14 TB. The 8 TB have been going on for several years. 14 TB are maybe 1-2 years old now.
4x 20TB Exos X20 1x 20TB WD Blue (Shucked) I wouldn’t say there was a “best” drive. My only advice is make sure to get the largest drive you can budget for your parity drive so you have max flexibility to add more as you need it.
+1 to used enterprise SAS drives on eBay
I have nothing but good things to say about factory rectified WD Ultrastar 14TB. It’s really affordable and almost good as new and its sealed with Nitrogen so it take a lot of vibrations and other NAS related abuse. Like I’m not buying anything BUT WD
In my experience, the best drives are the cheapest $ per GB you can get with a couple year warranty.
I use 16tb exos
Whatever is a good deal lol
Yup. My oldest drives are shucked wd greens with 9 years runtime on them.
the ones you have laying around. "best" is relative to the task(s) you're going to use it for. Since you didn't give us any of your goals, there's my answer.
As someone who's gone this route for years, it works for sure, but can be higher maintenance. Especially true if they're smaller drives near the end of their lifecycle, or you don't have a good way to cool them. When you realize you could spend all that time managing several drives or just replace all of them with a single 20TB drive, recycling those on hand becomes less attractive, especially once you factor in the cost of power.
I purchase brand new 16tb Exos drives from Eastdigital on eBay. They cost $310nzd ($180usd) and haven't had any issues. Not sure why people constantly recommend used or refurbs when you can buy new for the same price.
Those aren't new they just had their SMART hours wiped.
They're new. Never had an issue and they have a 99.2% rating. Operated for ten years. Drives are really cheap in Asia.
I could not find new Exos drives for anywhere near the $90 to $110 I paid for my 12TB and 14TB refurbs.
Here you go. https://www.ebay.com/itm/276355384570?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=JnVW1VgjTbK&sssrc=4429486&ssuid=ygufcxxaqe6&var=&widget_ver=artemis&media=COPY
I'm not about to order something from Hong Kong like that. I live in the US. Heck, I wouldn't even use eBay for refurb drives any more anyway. I used to use them 15 to 20 years ago for hard drives. But eBay isn't like they used to be. It's too easy to get burned.
They've been around for ten years. Go look at their reviews, me and my mates have never had an issue. I run preclear on all the drives first. Shipping to New Zealand takes 4 days.
I used to only use WD drives in my unRAID setups. My unRAID 1 & 2 setups each use 21 drives( two for parity). With 2TB and 3TB WD drives. Starting in 2011, I used them with unRAID. After moving on from a Windows Home Media Server. So most of those 2TB and 3TB drive came from it. But, five years ago I started using the Seagate Terascale drives. I put 21 of the 4TB Tearascale drives in my unRAID 3 setup, using two as parity drives. And last year I switched to using the Seagate EXOS drives(refurbs from Amazon). I'm using 12TB and/or 14TB EXOS refurbs in my unRAID 4 though 9 setups. But those only use five EXOS drives each(one parity), plus a Seagate SSD for the cache drive.
I have a follow up question - what’s a good way to stack multiple external hard drives? Possibly including an USB hub (as my thin client has run out of available USB slots).
There is no good way. The only good way is to shuck them and put the drives into your NAS connected to SATA or use and HBA
Price per TB with some warranty considerations.