Small Home FreeNAS System

[Daniel0059]

Hi everyone
I am currently building a new FreeNAS system for a friend and would like to ask the experts if it will FreeNAS:

• CPU Intel Pentium Gold G4600
• Mainboard ASRock RACK C236 WSI
• RAM 16GB Samsung DDR4 2400 MHz ECC
• PSU Sea Sonic G-450
• HDD 4x WD30EZRX 3TB
• Case Node 304
• System SSD Crucial BX500

It is only for home use (Photos, Videos and Documents) and I would set it up as RAID-Z2 so there should be ~5TB for storage.
Do you see any problems with this setup?

Thanks

 

[Chris Moore]

Case Node 304

If I recall correctly, this case has room for six drives. I would suggest putting all six in from the start as it is not possible to expand with just two more disks later. This may give excess capacity for now, but it will allow the system to be used longer before it needs significant modification to replace drives.

Mainboard ASRock RACK C236 WSI

This is a less than ideal board because it includes audio output that will never be useful and it does not include IPMI capability that is very useful. I would suggest that you look at the hardware suggestions here and see if you can find a suggested board that is available:

FreeNAS® Quick Hardware Guide
https://forums.freenas.org/index.php?resources/freenas®-quick-hardware-guide.7/

Hardware Recommendations Guide Rev 1e) 2017-05-06
https://forums.freenas.org/index.php?resources/hardware-recommendations-guide.12/

You do not need the latest generation hardware with FreeNAS. It is often better to go with slightly older hardware as it is less expensive and FreeNAS can not take advantage of some of the latest features.

 

[Chris Moore]

PS. Integrated GPU in the CPU is not an advantage as FreeNAS will not use it. FreeNAS only generates a text console locally.

 

[Holt Andrei Tiberiu]

You coud be better with a tower from entry models server's from dell and hp. These are designed for small office.
HP Ml30 or Dell t20
Power consumption may be better than the system described by you.
Raid z2 on 4 drives is..... not eficient.
Better do stripped mirrors (raid 10 )
Go for 6 drives in raidz2.

 

[danb35]

I would suggest putting all six in from the start as it is not possible to expand with just two more disks later. This may give excess capacity for now, but it will allow the system to be used longer before it needs significant modification to replace drives.

...of course, by the time capacity becomes an issue, RAIDZ expansion may have landed...

You coud be better with a tower from entry models server's from dell and hp.

That's often the most cost-effective way to go with new hardware, particularly for smaller systems, but I'm not aware of current good deals--do you know of any?

 

[Chris Moore]

by the time capacity becomes an issue, RAIDZ expansion may have landed...

We can hope.

but I'm not aware of current good deals--do you know of any?

There is a refurbished model on ServerSupply:
https://www.serversupply.com/produc...Wcb-qY5ZZuSMq7W_PCVxecyZv4_j2t0caAh1bEALw_wcB

 

[Antioch18]

Raid z2 on 4 drives is..... not eficient.
Better do stripped mirrors (raid 10 )

Would you please elaborate on this? Z2 may have more computational overhead but won't it offer better redundancy than a striped mirror?

 

[danb35]

Yes, Z2 offers better redundancy. Mirrors give more flexibility--you can easily expand by adding another pair of disks, and as of 11.2 you can even remove mirrored pairs from the pool too.

 

[Holt Andrei Tiberiu]

Would you please elaborate on this? Z2 may have more computational overhead but won't it offer better redundancy than a striped mirror?

for a 4 disk setup, i rather have performance than dual parity.
odd's of both drives from the same vdev to fail are extremely low, re-silvering in a 2 x mirror is much faster than in a z2 setup. ( no parity has to be calculated )
for a 6 disk setup i would definitely go with a z2 setup, for 4 disk, stripped mirrors.
Also on 4 disk setup with stripped mirrors, if you upgrade 2 of the disk's in the same vdev, capacity will automatically increase, in a raidz setup, you have to upgrade all the drives before the pool will auto-expand.
For example
2 x 2 tb stripped mirrors = 4 tb

vdev0
2 tb ad0
2 tb ad1
vdev1
2 tb ad3
2 rb ad4

if you change disk 0 and 1 with 4 tb model, you will have 6 tb of usable storage

vdev0
4 tb ad0
4 tb ad1
vdev1
2 tb ad3
2 tb ad4

 

[Antioch18]

vdev0
4 tb ad0
4 tb ad1
vdev1
2 tb ad3
2 tb ad4

In this case the additional 2TB capacity in vdev0 won't be striped, correct? If so, will you get different R/W perf from different addresses in the pool?

Also, in the case of ZFS mirrors, is bit rot still protected against? (I had always assumed, for what reason I don't know, that this came from the parity bits in RAID-Z).

Thanks for taking the time to explain, I appreciate it.

 

[Antioch18]

you can easily expand by adding another pair of disks.

How does this work? Does the mirror rebalance after the new vdev is added?

 

[danb35]

In this case the additional 2TB capacity in vdev0 won't be striped, correct?

It will eventually be striped as data is written to the pool, but not immediately after the disk upgrade.

Also, in the case of ZFS mirrors, is bit rot still protected against?

Bit rot is always protected against unless you explicitly disable checksums (which I don't believe FreeNAS lets you do through the GUI). In a single-disk pool or a pure striped pool, of course, it can't ordinarily be corrected (unless it's in metadata, which always has redundancy), but it will at least be noted. In a pool with redundancy, it will be corrected up to the limits of that redundancy.

 

[danb35]

Does the mirror rebalance after the new vdev is added?

No, not as such, though data will naturally balance across the pool as the pool is used.

 

[Holt Andrei Tiberiu]

In this case the additional 2TB capacity in vdev0 won't be striped, correct? If so, will you get different R/W perf from different addresses in the pool?

Also, in the case of ZFS mirrors, is bit rot still protected against? (I had always assumed, for what reason I don't know, that this came from the parity bits in RAID-Z).

Thanks for taking the time to explain, I appreciate it.

Performance from my point of view in this setup will be better than z2, because o parity not being calculated. In a stripped mirror you get always the best iops performance, in a raid z setup, you get the iops of a single drive, always the slowest drive.

 

[Holt Andrei Tiberiu]

PS, read this post. It explain's raid levels and performance.

Raid 5 is raidz
Raid 6 is raidz2
Raid 7 is raidz3
Raid 10 is stripped mirrors

https://www.google.com/amp/s/blog.storagecraft.com/raid-performance/amp/

 

[danb35]

It explain's raid levels and performance.

...with questionable (at best) relevance to ZFS.

 

[Holt Andrei Tiberiu]

...with questionable (at best) relevance to ZFS.

raid levels 0, 1, 10, 5 ,6, 7 and so on are the same.
ZFS did not re-invent raid levels. The math behind iops is the same, be it freenas or a hardware raid card.
That with ZFS i can have complex raid vdev's in the same pool, that i can mix z2 with z3, and use memory or fastt ssd as cache is another thing.
Logic is the same.

 

[joeschmuck]

There is a lot of "performance" talk here in this thread however what performance is required for this build? When I read the initial posting this is for basic storage, nothing fancy. The OP has yet to respond as well to voice their opinion as to all this. I would recommend that the basic hardware selection be commented on in order to provide what the OP has requested. My two cents is that a RAIDZ2 would easily fulfill the request. I just don't want to overwhelm the OP.

So with respect to the capacity, the four 3TB drives would provide you 5.5TB minus 20% (1.1TB) = 4.4TB of actual usable space. If you desire 5TB then either add a fifth hard drive or increase the hard drive size. If cost was not a factor then I'd add the extra hard drive but we all know cost is always a factor. The reason I'd add a fifth hard drive is to keep the resilvering speed as quick as possible and you get a little more capacity. But using four 4TB drives is also a viable option.

As my fellow forum members have stated above, sometimes a pre-built system is a less expensive way to enter this sector. @Chris Moore has referenced you to some good reading which you should do before buying anything. Also look at some of our system builds. Lastly, make sure you know what is expected of this NAS. if it's simple storage then you don't need a monster of a system, if you expect Plex Transcoding then you need some CPU horsepower, but if you plan to create a lot of Virtual Machines using Bhyve/iocage then you have more to consider.

My final comment... If you are building this for someone, be prepared to provide technical support, most people assume you will provide it. This is one reason I don't do stuff like this for people anymore, instead I provide them the URL's and will talk to them about it but if they build it then they can learn it and support it. Just some friendly advice.

 

[danb35]

ZFS did not re-invent raid levels.

It kind of did, actually. RAIDZ is not RAID5, and indeed has only superficial similarity. The big issue I see with that post is the assumption that any write necessarily involves reading data and all parity before writing it; there's just no reason that needs to be the case for ZFS. That alone cuts their stated penalty for all parity RAID levels in half.

 

[Daniel0059]

Wow thank you for the many comments and suggestions.

The CPU and the mainboard were already taken from the linked “Hardware Recommendations Guide”.

As joeschmuck has said the system is for basic storage. I will take the suggestion with the 5th hard drive into account then I can use all slots from the case I have selected (5 HDDs and the SSD).

The pre-built systems some of you mean are the FreeNAS Mini & Mini XL? Because the as far as I read bitrot can become a problem with Synology, QNAP, … that’s why I would rely on FreeNAS.