Make FreeNAS warn about non-ecc

[Michael Wulff Nielsen]

Here is my crazy thought for today (read it with a pinch of humor).

Since we know that somebody shows up every day with a gamer/consumer motherboard and asks if it is good for FreeNAS, I was thinking of a crazy addition to FreeNAS:

On first boot of a system:

If freenas detects non-ecc memory (*) pop a warning like:

"THIS SYSTEM DOES NOT HAVE ECC MEMORY, IT IS NOT SUITABLE FOR FREENAS. YOUR DATA WILL DIE AND WITH ZFS NOBODY HEARS YOUR SCREAMS."

Please type "I have read the warning and I understand the consequences" to continue.

#>

Of course to not be too annoying it should only do it on first boot.

Have a great day
/Michael

* - I assume that the operating system can detect ecc memory

 

[cyberjock]

That asterick is precisely the problem. There's a few ways you can identify ECC RAM in an Intel system if you know the precise chipset you are using, but if you don't know the precise chipset it won't work.

And AMD, well, you're just screwed at trying to identify ECC RAM on those.

Believe me, we've talked about it. But because there's no sure-fire way to detect ECC RAM any attempt would be full of problems.

On a similar but unrelated note we've talked about some kind of error message on bootup requiring user interaction if you don't have 8GB of RAM. I was alone in my recommendation that we add that on bootup. :P

 

[Michael Wulff Nielsen]

I thought as much. From my limited experience with low level programming on Intel systems I have learned to fear the chipset :)

Btw. I admire your patience with people that show up with the wrong kind of hardware.

 

[cyberjock]

I still really wish the 8GB limit was programmed into FreeNAS. I bet 10% of our questions would solve themselves just by virtue of them being unable to boot FreeNAS without interaction.

 

[Michael Wulff Nielsen]

Whats the argument for not doing that? Checking for 8GB of memory should work reliably.

 

[cyberjock]

Yes, but the powers that be don't want to force that kind of limitation on the software.

 

[DrKK]

I don't think the developers should "enforce" anything. i.e., I don't agree with CJ's 8GB-or-no-dice idea.

But, I would be certainly in EXTREMELY strong favor of a warning, at install time, that went something like this:

******* MEMORY WARNING FOR ALL NEW INSTALLS *******

FreeNAS is advanced, enterprise-class software. It expects, for reasons of reliability and stability, that certain system requirements (clearly enumerated in our published guides, and on our forums) are met. It will be your responsibility to verify that you meet these requirements. Most prominent among these:

1: That you have 8GB of installed RAM, or, approximately 1GB RAM per 1TB of storage, whichever is greater. If you do not meet this requirement, you can EXPECT that under certain conditions, your ZFS-based pool may experience a lack of performance, or reliability. Using FreeNAS on a system underspecified in total RAM will result in a dangerous condition, and you can expect little to no assistance from the developers, or the community, in the event that your FreeNAS install runs into problems.

2. That you have ECC (Error-Code-Correcting) RAM modules installed in your system. Few, if any, consumer-grade motherboards will support the installation of ECC RAM. Accordingly, FreeNAS should only be installed on server-grade equipment that support, and use, ECC RAM.

By proceeding, you acknowledge the dangers of using FreeNAS with important data when our published specifications and recommendation are not satisfied, and you further acknowledge that support from the community may be limited in these cases.

************************

Of course, the problem with this, is that certain people that will remain nameless that are intimately supporting the project (i.e., that own it), have been selling boxes to customers that don't have ECC RAM in them. So, to warn people against it, then to go ahead and sell the boxes...I'm not sure where that leaves anyone :)

 

[Michael Wulff Nielsen]

I think CJ and I both meant that the 8Gb warning should not prevent the system from installing. I think your warning is spot on, but it's too long and complicated and not scary enough ;).

As for selling boxes with non-ecc memory to customers when it is well known that a single scrub with defective memory can destroy your entire pool. That sounds downright dangerous and very scary to me.

I would imagine that some lawyers would have a field day with that. But since I don't live in the USA I don't know if it could be seen as willful neglect under US law.

 

[DrKK]

To say the least, this is a controversial topic with a variety of views.

 

[DrKK]

By the way sir, you are wrong. Cyberjock's view *IS* that the system SHOULD NOT BOOT UP/INSTALL without 8GB of RAM. (Trust me, I'm talking to him right now)

That is not my view...

 

[cyberjock]

No, I didn't want it to boot. Preventing installation is kind of pointless because:

1. People routinely install FreeNAS to USB from a spare machine and/or VM that might not have 8GB of RAM. Is it fair to deny installation on those grounds?
2. People routinely install FreeNAS by writing the image directly to USB. There is no installer in this case, so enforcement is pointless.

I wanted a warning on bootup or something. Even if it was just a warning that made you press a key to continue on bootup would be fine with me.

The reality of it is that this argument will be somewhat pointless as 9.2 is the last x86 build we will have. Simply by that we'll get rid alot of old systems. Sure, there will probably be some people with x64 CPUs and <8GB of RAM, but I think those numbers will be few and far between.

 

[Michael Wulff Nielsen]

On a warning-related note, is it considered good form on this forum to warn somebody off FreeNAS if it doesn't suit their needs? For instance if they insist on running on cheap consumer grade hardware.

Or perhaps people that want to store movies and don't care about data-integrity and so on. Many of these people with their cheap hardware would be better served by Linux and a non-checksumming filesystem.

Simply from the point of view that ext3 won't destroy stuff if there is memory corruption.

 

[cyberjock]

On a warning-related note, is it considered good form on this forum to warn somebody off FreeNAS if it doesn't suit their needs? For instance if they insist on running on cheap consumer grade hardware.

That's open for debate. I definitely do warn people(and of course I try to recommend options if Ihave some). Some people don't agree with this philosophy, but you won't get warned or banned in the forums for it.

Or perhaps people that want to store movies and don't care about data-integrity and so on. Many of these people with their cheap hardware would be better served by Linux and a non-checksumming filesystem.

Simply from the point of view that ext3 won't destroy stuff if there is memory corruption.

Normally if they don't have enough RAM but do have ECC I tell them to give NAS4Free a shot. It seems to work better with less RAM than FreeNAS does.

Often I just recommend they use their native OS and native file system. There's something to be said for using a file system and OS you are familiar with than something you aren't. If things go really bad and you are in a position where you are having to do data recovery, its a good thing to know the OS you are using. :)

 

[Michael Wulff Nielsen]

Thats nice, because after actually reading up on ZFS architecture and the design decisions, I can't in good conscience recommend that people use it unless they fulfill the requirements.

Also all that reading on data integrity has seriously made me reconsider my personal computers as well, but I can't recall seeing a laptop with ecc memory. And the only ecc memory mac is the new mac pro :(

I agree on the native os/filesystem as well.

 

[DrKK]

Really, if you're going to use consumer grade hardware, no ECC RAM, etc, and/or are trying to repurpose old hardware, there's really no reason you wouldn't just make a minimal Debian install and set up file sharing.