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NAS: a world apart!
#1
I'd need a NAS - Network Attached Storage - and apart the fact that it has drives inside and serve as file storage, I didn't know anything more really... so I made my homeworks, as usual, and a whole new world opened!

I thought it was easier - put the drives in, plug it to the PC and/or internet, and you presto! You are ready to go.

Not so fast, amigo!

Even if it's a matter of minutes to setup the basic settings, first question is: which NAS?!?

Almost everyone may agree that the most known and reliable brands are Qnap and Synology - someone would add Thecus, but here in Europe most, including me, never heard about it. That's it, only two main brands to choose from, what's the problem?

Apart that there are literally dozen brands around, some with even better price/quality ratio, I thought it's "better safe than sorry"... read many horror stories about other brands NASes that literally "eat" drives like candies, one after the other!

I also thought about using an old server - you know, the ones with A LOT of drive slots, like 12 or more... prices are quite affordable, often half or less the price of a NAS with the same number of bays. Not a wrong idea, per se, but... power consumption if several times more, so running one server 24/7 year round would cost in a year more than the difference of its price compared to normal NAS - so the break even point is only one year, and I hope that a good NAS would last more than that!

OK, were where I? Yes, no server - good idea but too expensive in the long run - so NAS, Synology or Qnap.

Now, several questions arise: brand new or used? Fresh used, or vintage? How many bays? Which RAID to set up? Which model? What processor? Which drives to use? What capacity?

New or used? Well, it depends on our budget, of course! I'm always keen to spend the same price for a top-of-the-line full fledged top model used, instead of a barebone basic new one. Sure, the new one has warranty, advanced technology, but as always "it depends"...

I'd go with used, then; but, fresh or vintage? Again about budget: if a fresh used one may be found for a nice price, let's take it; problem is, it seems that recent models retain high prices - I took a look around, and usually a two/three years model used is only 20% less than new... not worth it. Then vintage? Yep, is it possible to find them at dirty cheap price, but beware: they have several limits!

One, of course, is the speed: the oldest ones used ARM processor, with limited power and small memory; but the worst limit is capacity: some are limited to few TBs, while the best could top 16TB; not that bad, at the end; first problem is to find compatible drives (according to brands own compatibility list, they are limited often to 4/6TB drive), then, if you find the right size, when you need more storage space, you must buy a new NAS.

So, "in medio stat virtus"; an old model, still not vintage, would do: one with an Intel CPU - Atom, Celeron, Xeon, i3 etc. with no size limit could be a perfect balance between price and performance! The 16TB limitation is due to 32-bit operating system, but some intermediate model can use newer firmware to override this when a new array is made - but not when migrating to a different RAID version or adding more drives, so beware!

How many bays? Well, this is strictly related to the RAID configuration that we want to use. RAID 0 is the fastest, but if (when) a drive fails, all the data are lost! It must be used only for temporary content that must be served fast. After that, you could use RAID 1 - fast, but needs more drive; the only other choice apart the former using a 2 bay NAS.

What to use then? For small drive size and/or drive number, RAID 5 is a good compromise - you'll get N-1 drive capacity (for example using four 4TB drives you get (4-1)x4TB=12TB); the biggest disadvantege is that it could take literally days to rebuild the array if (again, when) a drive fails, and the biggest problem is, what if meanwhile another drive will fail? Not a so remote possibility, thinking that most likely all drives used there are of the same model/size (or even worst same batch); in that case, say farewell to your data...

Then RAID 6 is a better compromise if one wants to be more than sure (still, not 100%, but maybe 99.999%) that if something will go wrong, you'll not lose the data. It uses not only one reduntant drive, but two or more; so in our previous case of four 4TB drives, the whole capacity will be reduced to only 8TB; but in the not-so-impossible case that a second drive will fail during the array rebuild, you will not lose your data. Sure, then if a third drive fails... you must be the most unlucky person in the world (unless you set up three redundant drives...)

Back to bays: one, absolutely not, useless; no data protection at all. Two is the bare minimum, but in any case the total capacity is halved. Three, then? Well, you can use RAID 5 so better three than two; still, with four you can use also RAID 6 - if you need stronger data protection or you feel particularly unlucky! Then four bays - at least!

Models: too many to list here, and each model adds usually only a bit on top of the previous one, so better to carefully check technical data and then decide; for example, there are some models that have the same features of a more expensive one, but the display; do you really need a display in a NAS? It may be useful if you have to set it up without a PC, but who has not a PC nowadays? And the few ones without would probably not need a NAS anyway, so...

Processor, I've written before: an Intel one, the best/fastest model you can afford. Memory, again, the more, the better. A note: there are some models that use M.2 as read/write cache: this could improve a lot speed when using random small files, like database; still, almost useless serving big files on FTP.

Drives: avoid the desktop version, in particular low RPM (the so-called green); albeit perfect for home use, they are not made for sustained used, always on for several years! Then, the best would be enterprise, and NAS versions; also surveillance are better than desktop. WD or Seagate are the most used - possibly not only because of their quality, but also of their brand or compatibility, who knows... also, apart those, who still produce mechanical drives? Toshiba, and then who else?

Check the MTBF and the warranty - some enterprise models have five year, while most of the others have three, like NAS or surveillance. Of course an hard drive, as much as any other electronic device, will fail one or two days after the warranty is expired, so take it in account!

Finally, capacity... back to "old models but not too much": if you want/need more than 16TB in the (next) future, it's better to spend a bit more now, and put bigger drives, than discover that you can't add more drives without being forced to backup everything!

TO BE CLEAR: a RAID 1/5/6/10 is NOT a backup; sure, it is more robust than a single drive or JBOD/RAID 0, but there is always a chance that something could go wrong - someone that steal the NAS, a thunder that fries it, the cat that decide to pee on it because she does not like its smell etc. - then the best thing to do is to backup data routinely (depending on the refreshing data cycle) and possibly put the backup in another room/house/town/country/continent/planet/galaxy etc.

Which drive size then? Again, it depends... is the bigger the better still valid? Yes and no... personally I'd not use now 2 or 3TB drives - in a 4 bay NAS in RAID 5 you'll get only 6/9 TB total capacity - that you can have with two 6/10TB drives and RAID 1 even in a dual bay NAS. Then, 4TB is the minimum, I think. But again, remember the 16TB limit if your model is affected!

Let's see... 20TB drive price is quite steep; you can get 16TB ones for half price, so I'd take that size as maximum for now to be used in a NAS. Back to our possible four bay NAS, in a RAID 5 you can get (4-1)x16=48TB... not that bad! But... when (not if) a drive will fail, it will take I guess not only days, but weeks to rebuild the array... and the risk of a second drive failure is behind the corner! RAID 6 with 16TB will give you 32TB - only two thirds of RAID 5, but more robust data failure protection.

Still, do someone really need 32TB or even 48TB at home? Or more - what's about a twelve bay RAID 6 with 12x16TB for a gran total of (12-2)x16TB=160TB?!?

A budget conscious would probably go for "small" 8TB/10TB drives - a good compromise between space, cost, and rebuild time; for example, would it be better/cheaper/faster a four bay RAID 6 4x16TB=32TB, or a six bay RAID 6 6x8TB=32TB as well? If NAS price would be similar, I'd go for the second solution - cheaper main drives and spares, short rebuild price.

That's all, folks! Hope it could be useful for someone!

EDIT: forgot to mention: I was talking about tower/home NAS versions; rack ones are (usally) better versions due to build quality and often dual power supply - and they are more sexy, I must admit...
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#2
I personally prefer just setting up a dedicated server and using something like ZFS. A bit of a high learning curve, but well worth it IMHO. Upgrading your array is a lot easier, and depending on what kind of files you're storing there's a lot of options for filesystem level compression that can help a lot. If power usage is something you're concerned about, and you don't plan on using it for anything more then a fileserver, you can get something like an Intel Atom board that's built for low power consumption.
If you want to save a little money on drives, you can always look into "shucking". You'll void the warranty, but if buying a lot of drives you can save literally hundreds (at least in the US, can't speak for anywhere else)

Also don't forget to get yourself a good UPS.
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#3
I would throw in another (but more expensive) option: a m1 or m1x/m2 mac mini + a DAS. 
So you can use your mac mini as usual but it runs 24/7 or as long as you want it to as a server. The apple silicons are quite attractive because of their power consumption in idle and load, more so if you run it as an plex/jellyfin server + better transcoding if you want to stream your movies on to other devices outside of your local network.
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#4
UPS: is on my plan! Wink

Server: what price are we talking about? Consumption?

Mac Mini: I thought also about something like that - think that now you can use a TV box (that costs next to nothing) to run an FTP server! Problem is, how much will last, always connected? Few months?

I think (and maybe I'm wrong) a NAS with RAID 5 (or better RAID 6) - with a proper backup and an UPS - should have the right balance between initial cost, power consumption, data loss protection, easy of use.
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#5
(2021-12-16, 05:55 PM)spoRv Wrote: Server: what price are we talking about? Consumption?
I built my last file server for ~$1000. But I just looked through similar components and prices have gone way up even for used parts. As far as power consumption goes I haven't measured it but I built this one for low power cost and the increase in my power bill was negligible. 
(2021-12-16, 05:55 PM)spoRv Wrote: I think (and maybe I'm wrong) a NAS with RAID 5 (or better RAID 6) - with a proper backup and an UPS - should have the right balance between initial cost, power consumption, data loss protection, easy of use.
Yeah, you'd be right. You should just be aware of the major downsides of a NAS:
  • Minimal Functionality - if you want to host or run anything but a file server there's little or nothing you can do for most units
  • Security - You're at the mercy of the vendor for security/updates. There's been several cases of major bugs popping up in old units and the vendor not supporting or patching it.
  • Data Integrity - If the NAS fails it can be difficult or impossible to recover any of your data.
  • Quality - Most NAS's are made to be low-cost consumer units, and may not hold up as well over the years. I have enterprise server equipment that has been running 24/7 for almost a decade just fine.


I manage Datacenters/Infrastructure for a living, so if you have any other questions I'll do my best to help  Big Grin
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#6
Well, server and NAS are made for different task: actually, a NAS is a very specialized server, that basically serves files.

I'm aware of its limitations, but if all I want is to use it to share files, I think it's a good compromise; answering to the downsides:
  • Minimal Functionality - as file server, NAS is perfect
  • Security - I'm aware of this; I'd like to get an old model but that is "secure enough"
  • Data Integrity - I'll pose questions later
  • Quality - I'd stay away from cheap/low quality ones
Data integrity: let's say that I have a four (or more) bays NAS, and I want to preserve data as better as possible; apart of course backups, the "normal" RAID levels are 6 (with two or more parity drives) and 5 (with one parity drive).

AFAIK the NAS (or server, or PC) creates a single volume that will be the sum of the non-parity drives; so if I have RAID 5 four drives, I'll get the total capacity of three drives, with RAID 6 of two drives. They are "interconnected" and dependant also from their position inside the NAS, if I well understood roaming on various NAS forums in the last days.

Now, let's say that I have a NAS with four drives (1 2 3 4) in RAID 5 and I want to migrate to a new NAS; I should put the drives in the same order (1 2 3 4) in a new NAS and they should retain the data (giving it the right commands, I guess), even if it's not of the same brand, and even if it has more than four bays, right?

Also, for the limit that I wrote in my first post, if I have a less-than-16TB volume (like four 4TB drives in RAID 5) and I want to upgrade to bigger drives, I should backup the data to another "place" (be it a single drive, a NAS, backup tape etc.) of at least (4 drives - 1 parity = 3 drives) x 4TB = 12 TB.

If the previous answer is positive, I am "supposed" to take the drives in order (1 2 3 4), put them in my PC in the same order (1 2 3 4), and they are "supposed" to be there; then I can put the new drives in the NAS (let's say 4x6TB/8TB/etc) and then copy the whole data of the old drives, that temporally reside into my PC, to the NAS. Is it right? If so, this avoid the need to buy (or rent or borrow) 12TB drive/NAS for backup purposes. At the end, those drives will be the backup (of data stuck at the migration time) that, for any eventuality, could be retrieved in a second time. Or, better, after the data will be securily copied back into the NAS, they can be formatted so they could retain 16TB and not 12TB.

(my own head is spinning now... gimme a moment... fine, I'm back!)

Is there a RAID mode, or another way, to do the following?
Create X volumes, one for each of the X drives that I will put in the NAS (that has X+1 or X+2 bays), add 1 or 2 drives as parity, and then in case of data corruption the NAS will recovery lost data and repair the volumes, so for example I can take out one of the X volumes, put it in any computer, and it will be recognized?

In that case, it would be possible to make "mirror backup" (drive 1 has backup 1, drive 2 has backup 2 and so on), and if a drive fails, copy only its data will be possible (if we have two backups for drive, just put one of the backups

Sorry for the long post! Big Grin
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#7
(2021-12-17, 11:06 AM)spoRv Wrote: Now, let's say that I have a NAS with four drives (1 2 3 4) in RAID 5 and I want to migrate to a new NAS; I should put the drives in the same order (1 2 3 4) in a new NAS and they should retain the data (giving it the right commands, I guess), even if it's not of the same brand, and even if it has more than four bays, right?
With most hardware RAID cards, you're pretty much locked to that specific RAID card. Hence why I mentioned data integrity as a major downside. Sometimes you might get lucky and find an exact match for current RAID card and be able to recover your data, but I wouldn't depend on that. Most of the time when your RAID card/NAS dies, you're SOL for recovering any data. Software RAID doesn't have this problem, you can plug your array into any computer and you'll have no issue.
(2021-12-17, 11:06 AM)spoRv Wrote: Also, for the limit that I wrote in my first post, if I have a less-than-16TB volume (like four 4TB drives in RAID 5) and I want to upgrade to bigger drives, I should backup the data to another "place" (be it a single drive, a NAS, backup tape etc.) of at least (4 drives - 1 parity = 3 drives) x 4TB = 12 TB.
Just upgrade the drives one at a time. You can just remove the old drive and swap in a bigger one, the RAID will rebuild itself on the new drive and you're good to go. You won't be able to use the extra space until all 4 drives are upgraded, and then you have to expand the storage on the RAID card and then filesystem. Some cards handle this better then others, and I wouldn't make any changes in that respect unless you have a full backup. Software RAIDs generally handle this better, ZFS is great because it will automatically expand as you add drives without any additional work.
(2021-12-17, 11:06 AM)spoRv Wrote: If the previous answer is positive, I am "supposed" to take the drives in order (1 2 3 4), put them in my PC in the same order (1 2 3 4), and they are "supposed" to be there; then I can put the new drives in the NAS (let's say 4x6TB/8TB/etc) and then copy the whole data of the old drives, that temporally reside into my PC, to the NAS. Is it right? If so, this avoid the need to buy (or rent or borrow) 12TB drive/NAS for backup purposes. At the end, those drives will be the backup (of data stuck at the migration time) that, for any eventuality, could be retrieved in a second time. Or, better, after the data will be securily copied back into the NAS, they can be formatted so they could retain 16TB and not 12TB.
Nope, like I said those drives will be pretty much locked to that specific NAS.
(2021-12-17, 11:06 AM)spoRv Wrote: Is there a RAID mode, or another way, to do the following?
Create X volumes, one for each of the X drives that I will put in the NAS (that has X+1 or X+2 bays), add 1 or 2 drives as parity, and then in case of data corruption the NAS will recovery lost data and repair the volumes, so for example I can take out one of the X volumes, put it in any computer, and it will be recognized?
Not really something RAID is meant for. 


If you still want to go with a NAS, for best protection I would say either get a second NAS to mirror your data onto, or if it's not too large of an array you can get a large HDD and make backups so you don't have to deal with the nightmare of recovering data from a RAID.
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#8
(2021-12-17, 03:58 PM)stwd4nder2 Wrote: If you still want to go with a NAS, for best protection I would say either get a second NAS to mirror your data onto, or if it's not too large of an array you can get a large HDD and make backups so you don't have to deal with the nightmare of recovering data from a RAID.

I guess that if the total NAS space is 12/16TB, a single drive backup is easier and cost effective than a NAS + small drives!

Also, another way is, if it's a shared server, to any user to backup at least a chuck of data, so let's say 16TB with 16 users, 1TB each - or better 2TB each as double backup.

And thanks for all the other answers, too! Ok
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#9
I went with unRAID simply because i already have various servers running 24/7 (Plex and resilio for example). I can now run them all on the unRAID server. Also, the jbod with parity setup offers redundancy along with the ease of a jbod. I set the disks to go into standby after 30 minutes and the whole setup uses around 20-30w unless I'm streaming or something. Ryzen 7 1800x is the processor i have in it currently. 8x8tb WD red plus and a 2tb m.2 cache drive.

Just my two cents but if you are going to be running various servers anyway then unRAID is a good option.
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#10
With unRAID, you mean "de-RAID" a RAID setup, or use the https://unraid.net service?

Idea is to set up a server that will serve only files online, so not online+locally. And, as it could be accessed any moment of the day, or night, it should be on 24/7/365. Hence I guess a 4/5/6 NAS even full of hard drives should be around 50/60W.

Now a question arises: is it possible to put the NAS in sleeping mode after X minutes of no activity, and then if someone remotely requests a file, it will "wake up"? (of course modem/router will be always on)
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