FreeNAS for media/backup server

[burney]

After a few days of browsing this forum and the guides, I think I've arrived at a good setup, but I'd love to hear your opinion on it, and I've also got some questions.

So the main usecase will be to provide a file share for my Kodi mediacenter. I'm also thinking about using some of my old drives in a seperate pool for backup of photos and documents and stuff like that.

• Case: Supermicro SuperChassis 836BE16 (16 bays)
• PSU: 2x Supermicro PWS-721P-1R 80+ 720W (included with the case)
• MoBo: Supermicro X11SSL-CF
• RAM: Crucial DIMM Kit 32GB, DDR4-2133, CL15, ECC (CT2K16G4WFD8213)
• CPU: Intel Pentium G4400
• HDDs: starting with 6x 6TB WD Red in RAIDZ2

I've already bought the case (and the PSUs).

I've got the following questions/thoughts:

• The motherboard comes with a SAS controller on board which should connect to all drives on the backplane via one cable, right?
• As I mentioned, I might reuse some older drives. Specifically I have 6 drives, in sizes ranging from 2TB to 6TB, all WD Greens. I would need to create 2TB partitions on each of them, which I'd put in an RAIDZ2 array for the backup stuff. I'd also like to use the remaining space on the larger drives to create another pool, probably for some temp stuff, but nothing that relates to the first pool (as to prevent stress on the drives that provide space to both pools). Another possibilty would be to just use the remaining drives as single shares, since I woudn't need redundancy there. But given that I (theoratically) can put all old drives (totalling 20TB) to use, do you think that the 32GB RAM would still be enough for acceptable performace? Or would you generally advise against reusing the drives in such a way?
• What would you say about the futureproof-ness of this build? Given the 16 bays and mainboard limit of 64GB RAM? The next expansion step would be to add another 6 drive vdev (or maybe 2x 5 drive vdevs, to max out the 16 bays), but at the time I need to do that, I could probably get 10TB drives or even more for the same price I'm paying today for the 6TB versions. So I'm worried that the 64GB limit might not be enough for future expansion.

Please share your thoughts on this.

 

[Stux]

It gets expensive to break past the 64GB limit of the LGA1151 platform. At least you're not limited to 32GB :)

(Ie Xeon D or LGA2011-3)

Your thoughts and plans seem fairly sound too me.

 

[joeschmuck]

As I mentioned, I might reuse some older drives. Specifically I have 6 drives, in sizes ranging from 2TB to 6TB, all WD Greens. I would need to create 2TB partitions on each of them, which I'd put in an RAIDZ2 array for the backup stuff.

Nope, you would not partition them, FreeNAS would do this automatically. The smallest drive in the vdev will restrict overall capacity. I would advise against single drive pools but as long as you understand the risks...

What would you say about the futureproof-ness of this build? Given the 16 bays and mainboard limit of 64GB RAM? The next expansion step would be to add another 6 drive vdev (or maybe 2x 5 drive vdevs, to max out the 16 bays), but at the time I need to do that, I could probably get 10TB drives or even more for the same price I'm paying today for the 6TB versions. So I'm worried that the 64GB limit might not be enough for future expansion.

Future proofing is what we all desire but eventually we will want to replace it with the next faster product. But as for RAM, given your use case you could run 8GB RAM and be fine. You stated you only need to provide storage to Kodi and then a few more pools for personal stuff, right. 16GB RAM would be the minimum I'd actually recommend for anyone building a new system but if you want 32GB RAM, that is fine. If you think you will play around with building VMs then you should rethink the CPU and find something faster and start with 32GB RAM but plan for 64GB RAM.

Again, if you are just sharing data and making backups, I think you could just drop the RAM to 16GB if you want to save some money.

 

[Stux]

It is actually possible to do the partition stuff and make a 2TB partition on all the misc drives, then have a fairly stable raudz2 across that, and then use the remaining space for other purposes.

 

[burney]

It is actually possible to do the partition stuff and make a 2TB partition on all the misc drives, then have a fairly stable raudz2 across that, and then use the remaining space for other purposes.

Yeah that's what I had in mind.

Again, if you are just sharing data and making backups, I think you could just drop the RAM to 16GB if you want to save some money.

Ok great will do!
But now I'm confused about the 1GB RAM per TB Storage rule. I've also read here that "8GB of RAM will get you through the 24TB range. Beyond that 16GB is a safer minimum, and once you get past 100TB of storage, 32GB is recommended."
Can someone explain in what usecase which rule would apply?

 

[Dice]

What would you say about the futureproof-ness of this build?

I'd consider aiming for 7 or 8 drive wide raidz2 considering you are limited to 16 drives in that case.
7 drive wide gives you the additional space for comfortable safe resilvering process without removing the old drive first.
8 drives gives you none of that.
6 drives would conversely leave you with 4 empty slots, if not interested in for example setting up a Vm pool or something along those lines.
If using SSDs, you <could> just plunge them down in the case tucked away.
My own bet would be 7 drives.

 

[joeschmuck]

It is actually possible to do the partition stuff and make a 2TB partition on all the misc drives, then have a fairly stable raudz2 across that, and then use the remaining space for other purposes.

While it may be possible I think the real question is should you do it? If the OP wants to use all the drive space then I would say to stick with individual drive pools. Or just not use them at all. Keep in mind that the OP is new to this stuff and doing something advanced like this is asking for trouble so I say it again, should this be done, not can this be done?

But now I'm confused about the 1GB RAM per TB Storage rule.

In that link you also read that it's a complicated thing to figure out how much RAM you need. It's complicated directly by the use case because the rule doesn't take into account how the server is being used, it's generalized which makes the advice not very accurate. Honestly, you could get away wtih 8GB RAM but 16GB would be the minimum for future proofing as that would be 1 stick of RAM, leaving three slots open for three more sticks of 16GB if you needed to add more. You eventually will understand the uses of the RAM in FreeNAS but in a quick nut shell it is for caching your data both for writing it to the hard drives and for storing what is determined to be read the most frequently from the hard drives, and this doens't work for movies really but if you had a database that was accessed frequently then it would have a copy stored in the RAM for fast access to your users. This isn't what you are doing so though. If you needed iSCSI support then the minimum is 32GB regardless of the pool size but I'd recommend the full 64GB if this was the path you were serious about. iSCSI just needs a lot of RAM for stability and performance reasons. If you plan to run Virtual Machines then you should have some RAM for that as well.

While I fully understand that you want to jump into FreeNAS and buy your gear, there is a lot of reading you need to do to understand how it works. So based on your use case I'd recommend a single stick of 16GB ECC RAM, however if you want to toss in 32GB that would be fine. Myself being in that situation last year, I purchased all 32GB of RAM (notice I have a similar motherboard as what you desire to purchase) at first, got my system running and then my use case changed and I purchased the rest of my RAM for a full 64GB capacity. I'm just saying 16GB would not cause your machine to run slower based on your current use case and you can add more at any time if you find you need it.

I hope this helps and doesn't confuse you more.

 

[gpsguy]

BTW, don't forget to run wdidle on your WD Greens.

all WD Greens

 

[burney]

@joeschmuck That was a great explanation about the RAM usage, thank you. I will go with 16GB.

About reusing the old drives, I'm actually still not sure about that myself. I might also use them in a desktop system but I know that once i created a vdev, I cannot just remove a drive. So I will start with the new drives and see where I can go from there.

I'd consider aiming for 7 or 8 drive wide raidz2 considering you are limited to 16 drives in that case.
7 drive wide gives you the additional space for comfortable safe resilvering process without removing the old drive first.

My inital idea was to go with 6+5+5 drives. I didn't even think about leaving spares for resilvering. I guess I'm now going with 7 drives like you suggested.

Thank you all for your input! This really seems to be a great community.