# NAS/SAN build - ZFS performance questions



## Bun-Bun (Jan 22, 2013)

I am trying to figure out performance metrics for ZFS and if my plan is even possible. 

First off the hardware. 

ASUS P8H77-I H77 mITX mobo
Xeon ES 1230 CPU (possibly undervolt/downclock)
16gb (2x8gb) DDR3 ram
6x 2TB LP drives
Intel NetEffect Net Effect NEO20-CX4 10GB Ethernet Cluster Server Adapter PCI-E (with matching on my desktop)

Connected to my desktop utilizing an iSCSI lun over the 10gbe connection. The intent is to remove all internal storage from my desktop computer save for the OS SSD.

With the above hardware is it possible to have throughput in excess of 200mb/s? With IOPS similar to that of a 2 drive DAS raid-0?

Would that powerful of a processor be required? Or could I get away with a dual core i3?

I have asked this on a couple different forums but no one can seem to answer me and instead tell me to buy an HP server. I am building the case myself and it is going to be very purpose built to my requirements. I just am unsure if ZFS can give me the performance I am desiring and how much CPU is actually required (I would like to buy the $100 cheaper i3 but will buy a 4c8t if I need to).


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## xibo (Jan 23, 2013)

A legitimate Xeon E3-1230 should be powerfull enough to provide 200MB/sec via iSCSI, provided the HDDs can provide it that fast (which won't be an issue either with 6 disks of the current generation).

I have no idea how Xeon ES units perform, nor if they even run FreeBSD.


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## Sebulon (Jan 23, 2013)

@Bun-Bun

I would think it all depends on how well those internal SATA-controllers work in FreeBSD. Hopefully, they work as intended and youÂ´d be all set. Worst case, they donÂ´t work at all, and youÂ´d be stuck without the possibility of adding a decend HBA since the MB only has one PCIe. CPU-wise seems almost overkill, it itsnÂ´t all that heavy really. That depends on what you want ZFS to do with the data. The worst throughput killers are dedup and heavy gzip compression. No dedup and ordinary compression(e.g. just "on") is easily handled by about any modern CPU, even the low-end ones.

Also worth remembering is to make sure to enable and use Jumbo Frames on the storage network. It will offload the CPU greatly having to send fewer packets over the wire. There are additional tweaks you can use, tuning the system for 10GbE:

https://calomel.org/network_performance.html
https://www.myricom.com/solutions/10-gigabit-ethernet/performance.html

/Sebulon


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## throAU (Jan 23, 2013)

Pretty sure you'll get the performance, especially on the first half of the disks.  Not sure about over iSCSI though, but I have benchmarked a 6 disk triple mirror ZFS setup and managed > 200MB/sec with Bonnie.

If you're going for a Xeon, have you considered ECC ram for better data integrity?  The box I tested in was a 3-4 year old PowerEdge 2950, drives were a mix of 1tb and 250MB SAS, so I think an i3 would be plenty of grunt.


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## wblock@ (Jan 23, 2013)

iSCSI does not have much of a speed reputation on FreeBSD.  That is probably going to be the weak spot.


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## usdmatt (Jan 23, 2013)

Apparently a kernel iSCSI target is under development[1] which should be in testing but I can find sod all about it on the Internet/mailing lists/svn/wiki/..., just a progress statement.

[1]http://www.freebsdfoundation.org/press/2012Dec-newsletter.shtml#Project3


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## Bun-Bun (Jan 25, 2013)

Thanks for the response guys. Further reading suggests the hardware is probably capable but that I should be looking to a OS or Nexenta or something for running iSCSI and getting infiniband fiber adapter instead of the CX4 one. 

So for now I bought a low power AMD C-60 fusion board and plan to build a small backup NAS and save up some money to build a SAN.

Here is my roughed out concept


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