Putting Together NAS with FreeNAS... RAID5

[smitbret]

The cheaper, although slightly higher wattage, way to get ECC: get a 7-series or later ASUS AM3+ mobo (you may have difficulty finding anything less than an 880G chipset these days though), Sempron 140 or 145, and bang, you have access to unregistered ECC RAM and a CPU that is heaps above Atom and can handle most home server loads without complaint. (If you want, you can get a Athlon II X2 or x4 or -e variant if you need more CPU horsepower, too.) If you already have a 7-series or later ASUS mobo then you can just repurpose that. I did, but my 7-series mobo broke after I accidentally touched it with a screwdriver, and by touch I mean gouged it. Else I would have had everything but ECC RAM already on hand to make a ZFS NAS box.

P.S. I don't think you read the entire article. Expanding a mirror, etc. easier. Also, the guy who said you need to know Linux to run ZFS is mistaken about that part. ZFS is not native to Linux first of all, and FreeNAS/NAS4Free/OI+Napp It are easy ways to set up a NAS without having to know much of anything about FreeBSD/Linux/etc.

AM3 or AM3+?

I've got an ASUS M4A87TD EVO that's an AM3 with SB850 chipset. If that's a possibility, I may repurpose my current tower to the server since I won't need all of the HDD space anymore. Then I couldl pick up a MicroATX MB, FX-6100 (or 8-core) and a smaller case for the personal PC <sweeeeet>. I'm not a fan of Atom, I'll stick with a low power AMD Trinity or Sandy Bridge Celeron if I can't repurpose my current CPU/MB.

I read that about the ease of mirror expansion and had already read up on it a little, but the $$$ I'd invest would be better spent on storage space rather than redundancy.

Thanks for the reassurance on the Linux. I installed FreeNAS on my system just as a quick run through to see how hard it was and it was pretty simple. Had a volume set up off of a couple of old IDE drives so I feel good about my ability to use it. Feel even better now.

 

[taltamir]

How long have you been running this array?/QUOTE]

Several years.

- Recommend 1GB of memory for every TB of data storage. If you are doing dedupe then this increases significantly.

where do you get that figure?
I searched for it and found statements that the ARC (read cache, similar to windows superfetch) uses 1GB per 1TB... but if that is the case its not actually NEEDED.
Dedup however requires obscene amounts of ram (~2GB per 1TB in addition to all other ram requirements) and it is absolutely required (it CAN do it off the HDD but you will see performance tank by several orders of magnitude of that occurs to the point where the array is unusable)

 

[smitbret]

How long have you been running this array?/QUOTE]

Several years.



where do you get that figure?
I searched for it and found statements that the ARC (read cache, similar to windows superfetch) uses 1GB per 1TB... but if that is the case its not actually NEEDED.
Dedup however requires obscene amounts of ram (~2GB per 1TB in addition to all other ram requirements) and it is absolutely required (it CAN do it off the HDD but you will see performance tank by several orders of magnitude of that occurs to the point where the array is unusable)

I've read the 1TB=1GB of RAM in many different places so I'd go with 8GB for my 6-10TB array. It's only about $40 so,

Dedup seems like pretty big investment for little return, not to concerned about it.

 

[taltamir]

I prefer mirrors. I more or less agree with:

http://constantin.glez.de/blog/2010/01/home-server-raid-greed-and-why-mirroring-still-best

I also agree with it.
I have been using RAID5 and later on RAIDz2 (raid6 equivalent) for many years and I really should have gone with mirroring...
The problem is the cost of migrating from 5 drive array to multiple mirrors. (which wouldn't have been an issue had I had used mirrors to begin with)

 

[blastingcap]

Basically anything ASUS made for AMD starting with the 7-series supports ECC, except the APU sockets like FM1 not because it's ASUS's fault but because APUs don't support ECC RAM. So AM2+/3/3+ is fine... any of them. Your mobo should work fine with unbuffered/unregistered ECC; in fact, it even says so in the specifications:

http://www.asus.com/Motherboard/M4A87TD_EVO/#specifications

"DDR3 2000(O.C.)/1600/1333/1066 ECC,Non-ECC,Un-buffered Memory"

AM3 or AM3+?

I've got an ASUS M4A87TD EVO that's an AM3 with SB850 chipset. If that's a possibility, I may repurpose my current tower to the server since I won't need all of the HDD space anymore. Then I couldl pick up a MicroATX MB, FX-6100 (or 8-core) and a smaller case for the personal PC <sweeeeet>. I'm not a fan of Atom, I'll stick with a low power AMD Trinity or Sandy Bridge Celeron if I can't repurpose my current CPU/MB.

I read that about the ease of mirror expansion and had already read up on it a little, but the $$$ I'd invest would be better spent on storage space rather than redundancy.

Thanks for the reassurance on the Linux. I installed FreeNAS on my system just as a quick run through to see how hard it was and it was pretty simple. Had a volume set up off of a couple of old IDE drives so I feel good about my ability to use it. Feel even better now.

 

[blastingcap]

(~2GB per 1TB in addition to all other ram requirements)

Dedup requires something like 5GB per TB overall: http://constantin.glez.de/blog/2011/07/zfs-dedupe-or-not-dedupe (Others have calculated similar numbers, but I'm happy to keep giving Constantin hits haha)

Frankly dedup makes no sense for most home users. And if you really, REALLY want a bit of extra space, try compression instead. The lowest level is lzjb and doesn't hurt your CPU too badly, and it even gives a slight performance bump in some cases due the lower amount of data throughput necessary. http://sammitch.ca/2012/04/testing-zfs-compression-levels/ If you want stronger compression, I hope your CPU can handle it. You can always split the difference by compressing a dataset for highly compressible documents (basically it's a folder that you throw highly compressible documents into) and leaving the already-compressed stuff like .JPG's alone.

Edit: supplemental link to no less than Oracle itself re: compression: https://blogs.oracle.com/observatory/entry/zfs_compression_a_win_win Note that if you use something like NAS4Free you can do it all from drop-down menus in the browser interface, if you don't want to do it from the command line. I have a compressed dataset (think of it as a folder) using lzjb, but almost all of the stuff I put on my NAS is incompressible anyway, so my compressed-files lzjb folder is basically empty.

 

[taltamir]

thanks for the link blastingcap

 

[ch33zw1z]

http://www.freenas.org/images/resources/freenas8.3.0/freenas8.3_guide.html

section 1.4.2 is where I first read the RAM requirement for ZFS. I have no first hand experience, yet.

good thread.

 

[blastingcap]

thanks for the link blastingcap

No problem, and thank YOU for steering me towards ZFS in the first place, as I was at a similar crossroads as OP was at, last year.

 

[smitbret]

Looking at moving my existing desktop CPU/motherboard to the FreeNAS or unRAID box because it can take ECC memory. However, I don't understand if the 3TB HDD limitation is with the motherboard itself or with Windows.

Will FreeNAS support 3 TB drives from a MB that is not UEFI?

 

[Emulex]

sure, just boot off usb stick or ssd. Separate storage from o/s . trust me on that one.

btw there are many i3's that support ECC. RDIMM ECC is the best - it supports chipkill, address and data protection. UDIMM's only protect the data lines.

 

[smitbret]

sure, just boot off usb stick or ssd. Separate storage from o/s . trust me on that one.

btw there are many i3's that support ECC. RDIMM ECC is the best - it supports chipkill, address and data protection. UDIMM's only protect the data lines.

UDIMM=Unbuffered
RDIMM=Registered

Is that correct? Unfortunately, my board only supports unhindered.