NTFS vs ZFS and ECC dilemma

[anodos]

I'll equip the build with quiet fans also, not just the CPU cooler.
The fractal case is also silent oriented so that's my goal here, along with it being convenient to work with 8 drives and more.
But the important thing is the rig itself and the fans are secondary at best to our purpose here ;)

Bear in mind that keeping your hard drives cool is more important than being quiet. It also also more difficult than cooling a modern CPU.

 

[INCSlayer]

I'll equip the build with quiet fans also, not just the CPU cooler.
The fractal case is also silent oriented so that's my goal here, along with it being convenient to work with 8 drives and more.
But the important thing is the rig itself and the fans are secondary at best to our purpose here ;)

silent fans means low air movement that means hot harddrives and cooking your harddrives is never a good idea

 

[Eli Singer]

Actually, in the silent computing front i am quite invested for more than a few years.
I currently have 6 HDD's and 1 SSD in an antec p280 case and some high efficiency and very silent fans that i keep on 5v and my gear is cool as Fonzie. So although it is obvious that on the same fan, running in lower RPM would yield lower airflow than running it full speed, if you pick a good fan, you can have cool gear and a silent room.
If anyone is interested you can drop by at http://www.silentpcreview.com/ they are pretty much the authority for silent components fanatics :)

Eli

 

[john333]

I'd recommend looking at adding a UPS to your system. A UPS will give some protection against disturbances on the power line and also give time for the FreeNAS system to shut down in a controlled and safe way if you suffer a power outage.

 

[Eli Singer]

Yes i M definitely on the look for a UPS.
BTW, if i use UPS it actually makes BBU on a controller unnecessary?

Eli

 

[Ericloewe]

BBU on a controller unnecessary?

Hold it hold it hold it... There is no reason for one of the recommended SATA/SAS controllers to even have a battery.

 

[Eli Singer]

I saw that it is not advised to go with a RAID controller for FreeNAS for.some reason, i have to admit i didn't quite understand why that is, and i do know that the m1015 IS recommended so i still have to figure it out.
In any case, the question is relevant non the less, even if i will use a controller in my main machine and not in the FreeNAS server.

 

[Ericloewe]

Generally speaking, only a subset of problems solved by a BBU are actually solved by a UPS, too. It will depend on the controller and its caching policy.

 

[Eli Singer]

Could you explain that or point out where i can read about it?
Because my understanding is that if the UPS keeps the power up so the controller can finish writing and whatnot and then shutdown properly, so where does the BBU help here?

 

[Ericloewe]

Could you explain that or point out where i can read about it?
Because my understanding is that if the UPS keeps the power up so the controller can finish writing and whatnot and then shutdown properly, so where does the BBU help here?

Some scenarios off the top of my head:

• PSU fails. No amount of UPS backup will help you there.
• System panics and gets shut down before the controller is finished flushing its cache.

 

[Eli Singer]

PSU failure sounds pretty rare isn't it?
And it might cause problems only if the system is writing at the time of the failure right?
And usually the system is idle or reading and nor writing.
So it sounds like quite a stretch to go with BBU unless i'm missing something.

And why is it a problem with FreeNAS?

 

[Ericloewe]

And why is it a problem with FreeNAS?

With FreeNAS you wouldn't even have any sort of cache on the controller, so it's an academic discussion in this environment - you did mention some other system of yours though.

PSU failure sounds pretty rare isn't it?

Reasonably.

So it sounds like quite a stretch to go with BBU unless i'm missing something.

It depends on your requirements. Home user? Probably not worth it. Big business relying on a server's availability and integrity? Heck yeah.

 

[Mirfster]

It is best to always think in terms of "What could go wrong" instead of "I doubt that could go wrong"; using the latter will usually end up in "Oh S*$%!" moments.

 

[Eli Singer]

How does ZFS handles power failures?

My main machine is an editing suite and the intended FreeNAS server is for all the finished projects with the media files and all other personal files like music, photos etc.

Is it true that data loss on a power failure is problematic in writing situations only? Given that the system didn't burn of a power surge that is...

 

[Ericloewe]

How does ZFS handles power failures?

My main machine is an editing suite and the intended FreeNAS server is for all the finished projects with the media files and all other personal files like music, photos etc.

Is it true that data loss on a power failure is problematic in writing situations only? Given that the system didn't burn of a power surge that is...

It's resilient, but it won't magically protect your data. Unless you use sync writes, that is. In that case, it will magically protect your data. And drag it down to a crawl unless you get a proper SLOG device.

Loss of power is never good, but not much can go wrong when it's just reading.

 

[Eli Singer]

Never heard of SLOG, Google sent me here: http://www.freenas.org/blog/zfs-zil-and-slog-demystified/
So i should add another small SSD to the mix for SLOG?
I understand the performance benefits of it but not how it protects me when there's a power loss while writing...

 

[Ericloewe]

Never heard of SLOG, Google sent me here: http://www.freenas.org/blog/zfs-zil-and-slog-demystified/
So i should add another small SSD to the mix for SLOG?
I understand the performance benefits of it but not how it protects me when there's a power loss while writing...

No, let's not jump to conclusions.

An SLOG is only beneficial for sync writes. And it needs power loss protection (most SSDs with such a feature use supercaps instead of rechargeable batteries). The ZFS Intent Log protects your sync writes against power loss and similar scenarios, but it's sloooooow, compared to caching in system RAM. Therefore, it's normal to use a Separate Log device (hence SLOG) to offload this work from the pool to an SSD, which is better equipped to handle the workload - if there is such a workload, that is. Using CIFS, for instance, you don't have any sync writes.

 

[SweetAndLow]

Earlier you mention that you can't just take a zfs drive out and put it into a computer but I'll point out that the only os that doesn't support zfs is windows. Linux, osx, freebsd, etc all support zfs in some way. Also to reinstall and get your freenas system up and running takes 5min. You just boot from USB and you are done.

 

[Eli Singer]

No, let's not jump to conclusions.

An SLOG is only beneficial for sync writes. And it needs power loss protection (most SSDs with such a feature use supercaps instead of rechargeable batteries). The ZFS Intent Log protects your sync writes against power loss and similar scenarios, but it's sloooooow, compared to caching in system RAM. Therefore, it's normal to use a Separate Log device (hence SLOG) to offload this work from the pool to an SSD, which is better equipped to handle the workload - if there is such a workload, that is. Using CIFS, for instance, you don't have any sync writes.

Why wouldn't i use sync write for everything with SSD for SLOG? It looks like it is the more protected way (asynchronous writes use RAM which will be lost in case of a power failure), and fast (not as RAM, but enough).
What am i missing?

Eli

 

[Ericloewe]

Why wouldn't i use sync write for everything with SSD for SLOG? It looks like it is the more protected way (asynchronous writes use RAM which will be lost in case of a power failure), and fast (not as RAM, but enough).
What am i missing?

Eli

It's much, much slower.