Non ECC with ZFS

[adaq]

Hi, im goining to build a NAS to store my masive collection of pictures on and are going to run FreeNAS. I've been reading alot on diffrent forums about ZFS and if it is neccessary or not to use ECC when using ZFS. What do you guys say? Have you ever been using non ECC with ZFS? Experienced any problem? Is it really neccessary to use ECC for a home NAS? What are the risks and how high are them?

 

Thanks!

[79wjd]

It's not necessary, but if you can afford it, then I would. Scrubbing is an important part of ZFS and it doesn't really work without ECC memory (scrubbing is the act of "scanning" the drive and fixing any errors that are created in data).

 

/I ran my NAS without ECC for about a year without any problems whatsoever

[adaq]

2 minutes ago, djdwosk97 said:

It's not necessary, but if you can afford it, then I would. Scrubbing is an important part of ZFS and it doesn't really work without ECC memory. 

Okey thanks!

 

Could someone help me choose components for a nas build with ECC? I got a budget of 737,03 USD (6500SEK). I've got a psu at 175 watt already and 3 x 3TB WD Red should be included in the budget. My budget is somewhat flexible

[knightslugger]

I run FreeNAS without ECC memory as well, and so far so good. no errors or corrections. All my scrubs are good.

[knightslugger]

1 minute ago, adaq said:

Okey thanks!

 

Could someone help me choose components for a nas build with ECC? I got a budget of 737,03 USD (6500SEK). I've got a psu at 175 watt already and 3 x 3TB WD Red should be included in the budget. My budget is somewhat flexible

You don't really need a ton of spec. a SoC system will do you. If nothing else, budget in a UPS so that the system can safely shut down and avoid corruption. Also figure in having 5 disks for a RAIDz2 config.

[79wjd]

5 minutes ago, adaq said:

Okey thanks!

 

Could someone help me choose components for a nas build with ECC? I got a budget of 737,03 USD (6500SEK). I've got a psu at 175 watt already and 3 x 3TB WD Red should be included in the budget. My budget is somewhat flexible

I'd either go with a simple Skylake Pentium/i3 and a C232 board and 16gb of RAM if you want ECC. Otherwise, I'd check out a Kabylake Pentium. 

 

Also, what's the PSU? 

 

2 minutes ago, knightslugger said:

You don't really need a ton of spec. a SoC system will do you. If nothing else, budget in a UPS so that the system can safely shut down and avoid corruption. Also figure in having 5 disks for a RAIDz2 config.

True, something like a C2550d4i would be sufficient, but for that kind of money you can also get an i3, which is better (except in terms of power consumption -- but not enough to make a difference imo). There are also cheaper SoCs, but not that I would honestly consider. 

[adaq]

3 minutes ago, knightslugger said:

I run FreeNAS without ECC memory as well, and so far so good. no errors or corrections. All my scrubs are good.

Okey thanks, i've been thinking of geting those  components for my nas... Might be okey then? 

[79wjd]

1 minute ago, adaq said:

Okey thanks, i've been thinking of geting those  components for my nas... Might be okey then? 

You want at least 8gb of RAM. Most motherboards also come with sata cables. 

[adaq]

3 minutes ago, djdwosk97 said:

I'd either go with a simple Skylake Pentium/i3 and a C232 board and 16gb of RAM if you want ECC. Otherwise, I'd check out a Kabylake Pentium. 

 

Also, what's the PSU? 

 

True, something like a C2550d4i would be sufficient, but for that kind of money you can also get an i3, which is better (except in terms of power consumption -- but not enough to make a difference imo).

The psu is from a friends HP computer. He changed if becouse he needed more for his GPU

[79wjd]

1 minute ago, adaq said:

The psu is from a friends HP computer. He changed if becouse he needed more for his GPU

I'd probably replace it as it's probably junk. Something from tier 1-4 on the PSU tier list in my signature will do.

[adaq]

2 minutes ago, djdwosk97 said:

You want at least 8gb of RAM. Most motherboards also come with sata cables. 

Yeah i know, migh be difficult for you to se becouse its in swedish but it is 2 ram sticks in the cart

[79wjd]

2 minutes ago, adaq said:

Yeah i know, migh be difficult for you to se becouse its in swedish but it is 2 ram sticks in the cart

I'd get a single 8gb stick so you can add another stick in the future. I'd also recommend a Pentium+H110 board instead. 

[adaq]

1 minute ago, djdwosk97 said:

I'd probably replace it as it's probably junk. Something from tier 1-4 on the PSU tier list in my signature will do.

Okey thanks, but does i3 or pentium got support for ECC? might be worth buying a cheap pentium then insted? 

[79wjd]

1 minute ago, adaq said:

Okey thanks, but does i3 or pentium got support for ECC? might be worth buying a cheap pentium then insted? 

You still need a motherboard that supports ECC (C232/C236 chipsets). 

 

Skylake Pentiums/i3s support ECC. 

[knightslugger]

agreed, at least 8 GB of RAM for ZFS. Keep in mind you will need SATA power for the HDDs, and you will need more SATA connectors (so an add-on SATA card) for the hard drives that then baord offers.

 

i think that's a good board, just needs proper configuration for the hardware you want to put on it.

 

Stick with low power. it's not about the cost of electricity, it's about the longevity in case of a power failure. You don't want to be in the middle of a large transfer when the power fails only to find out the UPSs wont last but 15 minutes. Ask me how i know.

[adaq]

2 minutes ago, djdwosk97 said:

You still need a motherboard that supports ECC (C232/C236 chipsets). 

 

Skylake Pentiums/i3s support ECC. 

okey, thank you for clearing things out for me

 

Will take a look at some options and then might come back and se what you guys say

[Mikensan]

I second getting a single stick of 8gb incase you expand. If you're buying a new setup then buying a motherboard that supports ECC is about an extra $100us. ECC memory usually is only about $10-$20 more expensive.

 

It really depends on how paranoid you are. If you do not mind the cost, then go for it. Otherwise you don't have to have ECC and may never experience a bit flip. I have data that's over 15 years old that resided on computers without ECC (just as risky as FreeNAS) and no issues. 

 

ECC isn't a waste of money, but it certainly isn't needed.

 

[Electronics Wizardy]

On 1/26/2017 at 2:07 PM, djdwosk97 said:

It's not necessary, but if you can afford it, then I would. Scrubbing is an important part of ZFS and it doesn't really work without ECC memory (scrubbing is the act of "scanning" the drive and fixing any errors that are created in data).

 

/I ran my NAS without ECC for about a year without any problems whatsoever

Scrubbing isn't effected by ecc at all.

 

ZFS doesn't need ecc more than something like ntfs or btrfs would. Its always nice to have, but won't kill your data if youdon't.

[AshleyAshes]

https://arstechnica.com/civis/viewtopic.php?f=2&t=1235679&p=26303271#p26303271

 

Quote

There's nothing special about ZFS that requires/encourages the use of ECC RAM more so than any other filesystem. If you use UFS, EXT, NTFS, btrfs, etc without ECC RAM, you are just as much at risk as if you used ZFS without ECC RAM. Actually, ZFS can mitigate this risk to some degree if you enable the unsupported ZFS_DEBUG_MODIFY flag (zfs_flags=0x10). This will checksum the data while at rest in memory, and verify it before writing to disk, thus reducing the window of vulnerability from a memory error.

I would simply say: if you love your data, use ECC RAM. Additionally, use a filesystem that checksums your data, such as ZFS

To be clear, Matt Athren's was co-founder of ZFS when he was at Sun Microsystems and is now a ZFS developer for Delphix.  ...He probably knows a little more about ZFS than everyone who's ever told you that non-ECC memory and ZFS is some kind of secret sauce that is going to turn your data into Swiss cheese the moment you look at it the wrong way.

[79wjd]

5 hours ago, Electronics Wizardy said:

Scrubbing isn't effected by ecc at all.

Except that If you try to scrub your data with bad ram all three checksums will fail and you can corrupt your data whereas with ecc that wouldn't happen.

[Electronics Wizardy]

15 minutes ago, djdwosk97 said:

Except that If you try to scrub your data with bad ram all three checksums will fail and you can corrupt your data whereas with ecc that wouldn't happen.

Very unlikely for all three to fail. 

[79wjd]

31 minutes ago, Electronics Wizardy said:

Very unlikely for all three to fail. 

all the* checksums

[AshleyAshes]

I quote an actual ZFS dev and some people still think they know better.

[79wjd]

4 minutes ago, AshleyAshes said:

I quote an actual ZFS dev and some people still think they know better.

I'm not saying you MUST use ECC. In fact I said there was nothing wrong with not using ECC. And he's not saying there is no reason to not use ECC either -- he's saying that any OS has similar risks when not using ECC. Checksumming data (i.e. scrubbing) with bad memory will cause problems. 

[AshleyAshes]

8 minutes ago, djdwosk97 said:

I'm not saying you MUST use ECC. In fact I said there was nothing wrong with not using ECC. And he's not saying there is no reason to not use ECC either -- he's saying that any OS has similar risks when not using ECC. 

But you're silly parroting the false dooms day scenario that ZFS without ECC will suddenly destroy everything during a scrub when, actual ZFS devs dismiss it.  There's no risk in not using ECC than there is on any other file system, again, as stated by a ZFS dev.  But this only -ever- comes up during discussions of ZFS.  No one is warning everyone in the 'Storage Devices' section that NTFS without ECC memory could result in every bit of data lost!  (Let's not pretend that people do not keep important data on their boring consumer PCs or laptops that don't have ECC.  Heck, their MOST important data is usually there.)

 

It's still about the 'Evil Scrub' that ZFS devs have dismissed.  There their reasons to use ECC?  Sure.  ECC exists to prevent uncommon errors and if you can add it to a server, sure why not.  But if the home storage solutions running ZFS doesn't have ECC, there's negligible additional risk.  Honestly, concurrent hard drive failures or the PSU blowing up and taking out half the components hooked up to it is far, far, far, faaaaaaaaaaaaaaaar more likely.

 

This is just needless fear mongering.