# ZFS Hardware Requirements



## andyzammy (Sep 27, 2011)

Hi,

I've been thinking about building a NAS/Server (12TB RAIDZ) using ZFS and running XBMC, but don't know a lot about what ZFS requires to run smoothly. I know it needs a 64 bit CPU and as much RAM as possible but that's about it.

I'd like this server to consume as little power as possible. My original choice of using an atom board was abandoned after reading up a little on ZFS but now I don't know what to pick now, not knowing much about CPUs.

I'm also not sure about how practical a low power server is using ZFS, as I think that the drives are always spun up? Is this due to the striping? If so is there a way to disable it and still have raidz functionality?

Any help would be appreciated.


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## vermaden (Sep 27, 2011)

The more RAM, the better, but if You have 1GB RAM, then it will also do, I have here 2TB ZFS mirror (2 x 2TB drives):


```
$ uptime                                                                                                              
 9:43PM  up 115 days, 11:45, 4 users, load averages: 0.00, 0.00, 0.00
```


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## andyzammy (Sep 27, 2011)

vermaden said:
			
		

> The more RAM, the better, but if You have 1GB RAM, then it will also do, I have here 2TB ZFS mirror (2 x 2TB drives)



Sorry, missed out a crucial piece of info, the server I want to build will be made up of 6 2TB drives. Updated first post.


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## vermaden (Sep 28, 2011)

andyzammy said:
			
		

> I'd like this server to consume as little power as possible. My original choice of using an atom board was abandoned after reading up a little on ZFS but now I don't know what to pick now, not knowing much about CPUs.



Atom CPU is not a bad idea, just get the dual core one:
http://www.jzab.de/content/selfmade-nas-intel-d510-dualcore-atom-silent-storage-server



> I'm also not sure about how practical a low power server is using ZFS, as I think that the drives are always spun up? Is this due to the striping? If so is there a way to disable it and still have raidz functionality?



If You want it to be real low on power usage, then get 1TB 2.5 drives instead of 'desktop' 3.5 ones, it will lower the power draw drastically.

If You need 2TB drives, then You can get low power drives like _Seagate Barracuda LP 2TB_, they also use 'standard' 512B blocks.

I would get dual core *Atom D510 *or *D525* motherboard (the difference between *10 and *25 is that the first one uses DDR2 and DDR3) with 4GB RAM in one stick (which will give You room for 8GB RAM when needed).

The other option may be one of these (*Celeron *based on *Sandy Bridge*):
http://en.wikipedia.org/wiki/List_of_Intel_Celeron_microprocessors#.22Sandy_Bridge.22_.2832_nm.29

Or even one of these *Core i3-2100T*, *Core i3-2120T*, *Core i5-2390T*, they all have 35W TDP.


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## andyzammy (Sep 28, 2011)

The atom board I was thinking of getting was this one. I've recently learnt about an issue with the SATA ports where there is a port multiplier being used on the RAID ports. Someone I know has this board running unRAID and says he experiences transfer speeds ranging from 50-80MB/s but as that's a different NAS configuration I don't know how relevant his speeds are to my setup. I'm guessing that the striping will cause issues if there are 6 drives that are only able to use 2 or 3 actual SATA buses? Could anyone confirm this please?


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## vermaden (Sep 28, 2011)

@andyzammy

This ZOTAC board uses JMicron chip to provide additional 4 slots, but my experience with JMicron chipsets is pretty shitty at best, if You need more SATA ports from Intel Atom motherboard, then try SUPERMICRO which uses ICH9R for SATA ports: http://www.newegg.com/Product/Product.aspx?Item=N82E16813182242


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## bbzz (Oct 6, 2011)

andyzammy said:
			
		

> Hi,
> 
> I've been thinking about building a NAS/Server (12TB RAIDZ) using ZFS and running XBMC, but don't know a lot about what ZFS requires to run smoothly. I know it needs a 64 bit CPU and as much RAM as possible but that's about it.
> 
> ...




I was just going to add that you should consider running raidz2 with 6x2TB disks. Just a thought.


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## andyzammy (Nov 2, 2011)

vermaden said:
			
		

> @andyzammy
> 
> This ZOTAC board uses JMicron chip to provide additional 4 slots, but my experience with JMicron chipsets is pretty shitty at best, if You need more SATA ports from Intel Atom motherboard, then try SUPERMICRO which uses ICH9R for SATA ports: http://www.newegg.com/Product/Product.aspx?Item=N82E16813182242



Thank you very much for your help. I did spot this board but I originally didn't want it because at the time I wanted this server to be "all in one box", which would include hooking it up to the TV and watching directly from it. Zotac had a x16 PCI slot.

I've since changed direction and am separating the client from the server. I now have that motherboard sitting in my room. The x4 slot is perfect for expansion in the future. For a client I now need to find myself an aspire revo or equivalent (budget networkable 1080p HDMI box).

I should have been much quicker off the mark with this though, I will probably be waiting a very long time for my hard drives now.




			
				bbzz said:
			
		

> I was just going to add that you should consider running raidz2 with 6x2TB disks. Just a thought.



Thanks for the suggestion. I have considered it and still might try it out. As it's going to be a media server though (ie, not sentimental stuff), a concern is the % of space taken up by parity. I might instead just mirror one 2TB drive - more than enough than I need to sleep at night.

The most ideal solution to me though would be one with an unraid-like implementation. I know ZFS has the option to disable striping, but nowhere can I find any hint of a method of turning one HD into a "parity" drive. I assume because it's not implemented. But given the theory behind unraid, it's certainly possible. Guess not enough people are interested in it to make it.


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