Best specs for large storage-only NAS

[griest]

Hello all,

I am looking to build a high-capacity (24 drive) NAS. It will be storage-only for mostly media and backups; all transcoding, VM, and other server needs will be handled by a separate system. I plan on running FreeNAS.

I don't think I will need a very powerful processor or very much RAM, right? I will probably be running advanced RAID setups, I'm not sure how much processing power that needs. Should I prioritize single-threaded performance or core count? How well would RAID-related tasks scale with core count?

Mobo choice matters too. I would like 10gig, although that could be an add-in card. Obviously I need to make sure that I can connect all my drives; so extra PCIe slots would be nice. Space should not be a concern, this is the chassis I plan to get (12" x 13" form factor), although other suggestions are welcome.

If you could suggest a power-efficient CPU+mobo+RAM combo I would be most appreciative. I would prefer AMD platform if possible but functionality is most important.

 

[SRussell]

I would go with an X10 based motherboard with an L based Xeon processor. If you want hyper efficiency then a Xeon-D or Avoton 3xxx board would be best.

 

[griest]

@SRussell anything from AMD worthy of consideration? And what core/thread count and at what clock speed should I be looking for? Would 4C8T @ 3.2 GHz turbo be sufficient?

 

[gea]

I would prefer Intel due its proven server reliability. AMD offers CPUs at the moment with a better price/performance ratio (I use them for my 3d/rendering machines) but is focussed more on the gaming sector.

For 1G networks without encryption, CPU performance is quite uncritical. An 1151v2 board with a cheap i3 or Celereon is ok as they support ECC RAM (I would insist on ECC for a reliable high capacity storage system). CPU frequency is more important than cores

If you are looking for 10G and want > 500 MB/s read/write, you need a more performant CPU.

If you want to use ZFS encryption (currently available on native Oracle ZFS and Open-ZFS on Linux and Illumos/OmniOS, Free-BSD sometime in 2020) you also want a more performant CPU.

 

[ReturnedSword]

@gea Have you seen any numbers on ZFS encryption with regard to relative CPU performance needed? Currently on GELI I haven't seen it to be that CPU intensive, but of course the new ZFS encryption is much preferred.

 

[griest]

@gea thanks for the advice.

I don't need ZFS encryption but I do want high transfer rates, though high latency is not an issue. Considering that I might be running advanced RAID like RAID 60, would the Xeon E-2124G be sufficient?

 

[gea]

Raid-60 is traditional hardware or software raid on older filesystems. Without ZFS you should use a hardwareraid with cache and BBU protection to (mostly, not as perfect as ZFS Z2) avoid the write hole problem (corrupt raid on acrash during write), "Write hole" phenomenon in RAID5, RAID6, RAID1, and other arrays.

With softwareraid you need a faster CPU than with hardware raid.
A current CPU, far below your Xeon is capable for realtime 3D. You will not see any serious load effect due raid calcuations on softwareraid even with much higher throughput rates than possible with hardwareraid.

 

[griest]

@gea Well since I am planning on using ZFS, I guess I should use RAIDZ. I realized that I have an old i7-3770K that I can recycle for this system. Would that be powerful enough? Its an older chip but it is an i7...the only real issue is that I only have 8 GBs of RAM for it which I doubt will be enough.

 

[CreoleLakerFan]

@gea Well since I am planning on using ZFS, I guess I should use RAIDZ. I realized that I have an old i7-3770K that I can recycle for this system. Would that be powerful enough? Its an older chip but it is an i7...the only real issue is that I only have 8 GBs of RAM for it which I doubt will be enough.

Typically a consumer Intel is not going to support ECC RAM, which is a good thing to have on a ZFS server.

 

[gea]

There is no special reason to use ECC because of ZFS.
If you are looking for a secure storage server, use ECC.