DAT NAS build

Sonorous

Great thread! This may be my next project. Did you end up using a different file system to improve transfer speeds?

shwaip

Sonorous said:

Great thread! This may be my next project. Did you end up using a different file system to improve transfer speeds?

still using zfs/samba. file xfer speeds are fine for everything i do.

Butters

Thanks for sharing. This topic has actually come up amongst my co-workers, as well as the build vs buy argument. I'm leaning toward building now.

shwaip

newegg has the 2tb red drives on sale today (2 for $100 each)

http://www.newegg.com/Product/Product.aspx?Item=N82E16822236343

Butters

I almost created a clone of your system, but ended up going with an HP Microserver. Smaller footprint, but only 5 hdd max.

http://www.newegg.com/Product/Product.aspx?Item=N82E16859107921

boasist

Butters said:

I almost created a clone of your system, but ended up going with an HP Microserver. Smaller footprint, but only 5 hdd max.

http://www.newegg.com/Product/Product.aspx?Item=N82E16859107921

Interested how that may work out for you. I have the HP EX485 now, and have had it for about 5 years, so I'm in the market to upgrade. It already handles 1080p well, so anything I buy today will not be an issue.


How are you liking the Ubuntu managment? I was thinking of sticking with WHS or going with Server 2012.

Good thread you got here....

Annes

I think @pragtastic and I are going to do this with some of our extra cash before baby. Nothing says "I can get through maternity leave" like having a sexy NAS full of shiz. @thrax - what case and mobo were you recommending to me last night?

Thrax

Fractal Node 304, Asus E45M1-I DELUXE

Add RAM, HDDs and a PSU, and you're done.

shwaip

http://www.newegg.com/Product/Product.aspx?Item=N82E16822236344

$135 for WD 3TB red drives (according to slickdeals, i didn't check what the "extra savings" were).

@annes

fatcat

is there an advantage of raidz2 over doing an actual raid6? did the motherboard not support raid5/6 natively?

mertesn

What I'd like to know is what stripe size is optimal for the 3TB Red drives. They're listed as Advanced Format, so they use 4k sectors but report to the OS as 512b sectors.

shwaip

fatcat said:

is there an advantage of raidz2 over doing an actual raid6? did the motherboard not support raid5/6 natively?

it's software raid, so it's controller independent. as long as the os supports zfs, I can transfer the zfs pool to it.

edit: zfs has several other advantages that i'm not really considering/taking advantage of for my nas. it supports the addition of an ssd as a cache drive. it also lets you do deduplication (http://en.wikipedia.org/wiki/Data_deduplication) if you have enough memory.

BlackHawk

Bump!

I'm contemplating a build in January vs a Synology. How's yours running so far?

shwaip

BlackHawk said:

Bump!

I'm contemplating a build in January vs a Synology. How's yours running so far?

running well!

I reinstalled the os at one point to get a gui to play things on my tv. the zpool reinitialized just fine and was recognized by the new install no problem!

BlackHawk

So how exactly did you go about this? Did you reinstall your OS to make it a media center as well or just to display on your TV? What OS is it anyways? Software raid? How was it recognized after a re-installation?

shwaip

Step 1: zpool export
Step 2: install new OS (old os was server ubuntu, and i wanted to switch to mint)
Step 3: zpool import

i do have a separate ssd for the os, though.

immediately recognized with no issues

ardichoke

@fatcat said:
is there an advantage of raidz2 over doing an actual raid6? did the motherboard not support raid5/6 natively?

I know I'm reviving an old thread here, but I don't think this ever really got answered...

Reasons ZFS RAIDZ is superior:

• It is your RAID, volume manager and filesystem all in one allowing for optimizations that hardware RAID can't do
• Compression
• Deduplication (though you shouldn't use it unless you have an ungodly amount of RAM... also compression saves you more space in most workloads AND speeds up read/write times under most workloads)
• The aforementioned ability to use SSDs as an extra caching layer
• Rebuilding a RAIDZ after a drive replacement requires only rebuilding blocks that are in use, whereas a hardware RAID array must rebuild all blocks in the array since a hardware RAID array is not aware of data at the filesystem level
• RAIDZ keeps checksums of all the files, allowing it to detect (and typically correct) bit-flip corruption. Standard hardware arrays can sometimes detect corruption like this, but it's only informative, it cannot correct the issue.
• Copy-on-write. Granted, you could get this on a standard RAID array if you used a CoW filesystem, but still, it's a great feature.
• RAID expansion on the fly. Hardware RAID requires that all drives must be replaced before you can expand your array size (if the hardware even allows you to do it at all). ZFS will intelligently scale the size of your pool as available drives change as long as it can maintain the required level of redundancy by spreading checksums around. This allows you to make better use of mismatched sized drives without being limited to n*(size of the smallest drive). (See the SHR in the Synology RAID Calculator for examples of what I mean. It's not the same as ZFS, but it functions using the same principles and I can't find a ZFS calculator right now. See also, the Synology Hybrid RAID explaination, once again, different implementation of the same principle)

Reasons hardware RAID is superior:

• Slightly better performance (and I do mean SLIGHTLY, ZFS has closed that gap a lot)
• Typically offloads RAID calculations to a hardware coprocessor on the controller, thus reducing CPU overhead.
• RAIDZ tends to be a little heavy on RAM usage

Also of note: the onboard RAID on your motherboard? Yeah, it's not really hardware RAID. It's basically a software RAID implementation in your motherboard's firmware. It will probably perform a little better than actual OS level software RAID, but it won't give you anywhere near the performance increase of a true hardware RAID card (which typically cost at least $100 on their own).

For the self-built home NAS, there really is no compelling reason I can think of to choose motherboard RAID over ZFS.

mertesn

So...what do you define as an 'ungodly' amount of RAM?

shwaip

random search results:

For every TB of pool data, you should expect 5 GB of dedup table data, assuming an average block size of 64K.
This means you should plan for at least 20GB of system RAM per TB of pool data, if you want to keep the dedup table in RAM, plus any extra memory for other metadata, plus an extra GB for the OS.

mertesn

Hm...36TB array, 20GB per TB...

ouch.

ardichoke

Yeah, the dedup feature in ZFS is really meant for enterprises that are storing massive quantities of data and are willing to spend a lot of money to do it as efficiently as possible. Really not for home use. Also, it probably won't even save that much space on home workloads. Block level deduplication is really only worth it at incredibly large scales (think cloud storage providers).