Some questions to start with FreeNAS

[karnalta]

Hi all,

I want to build up a custum NAS with FreeNAS but as a newbie in that domain I have several questions, I hope someone will be nice to answer them ^^

1. Is it best to use the software RAID5 or the hardware one ? Knowing that the NAS motherboard is an old P45 chipset.

2. The documentation say that 8Gb is a minimum for good performance, is that real ? It's look like big amount of memory just to do file sharing ?

3. I want to build my NAS in three phases, but I am not sure things are going to work as I'd like. Here is how I am thinking of doing it :

A. Creating the NAS with my current old computer hardware, I will do RAID 5 with 4 drives (2x 500gb 2x 1000gb). I will have 1.5To of storage right ?

B. Buy two new 1To drive, to replace the two old 500gb one. I will replace them one by one and let to the OS the time to recreate raid data. I will not loose any data by doing this that way ?

C. Buy a new Micro ATX motherboard and a new small case. But how will react FreeNAS when I will restart it on a totally new hardware (MB, Network adapter, ...) ? If you do such a thing to a windows computer, there is no chance for it to boot up again ..
​

Sorry for the long post, but I really need help on these points, thank a lot for your help.

Regards

 

[Bohs Hansen]

Personally I'm no big fan of Raid. Reason, if the hardware fails you'll have to get the same again to recover your data. ZFS is more userfriendly in that area.
ZFS is also the reason for the "big" amount of ram needed. If you go with Raid or UFS instead you won't need so much. But then again, considering you get decent quality 8gb (2x4) for around 50euro, why safe in that area?

About your disk questions and upgrade of them, I'll leave the answer of that to someone else. Personally I don't like mixing different size drives in the same pool.
However a little input.. if you chose to use ZFS you could make 2 pools of the 2 different drives and add them together and it would result in that size. Raid itself will always use the size of the smallest disks as base - so the 1tb drives are kinda waste then.

About new hardware, that should be as simple as exporting the settings from your old system and importing them in the new.

But you should wait for more replies from the "real" guru's here, they know best. Hope I made a little sense anyway

 

[karnalta]

Thank for your answer Bohs.

For my question 1 & 2, I think your response is right, I will go with ZFS and that's why 8gb is a good choice to get good performances.

For the others points, I want to have one big storage space, that's why I wanted to put all drive in raid 5, I know at first I will lose disk space cause the smallest 500gb will be taken for the raid size. But I planning to soon replace them with 1To and that's the purpose of my question.

Finally, about my new hardware, why did you say "that should be as simple as exporting the settings from your old system and importing them in the new" ? FreeNAS is not installed on the RAID array ? FreeNAS has drivers for hardware or so ? I really don't know anything about FreeBSD OS. I'am trying to imagine the same situation into a Windows environment.

 

[joeschmuck]

To respond to the last question... Since FreeNAS is not bound to the specific hardware you created your NAS on you can move it to another computer. Device drivers are loaded during the boot sequence and have virtually no impact to a previous configuration. You might have the LAN connection labeled different and the hard drives might have different controller assignments but the level of effort to reestablish the NAS will be minimal and your data "should" be safe. I use should only because you could recreate the RIAD and destroy your data easily if you're not careful. You want to use the Auto Import feature which so far has been working well.

As for the minimum RAM, I'm using 4GB and haven't had a single problem but then again I don't have a dozen hard drives either. If you can get 8GB that would be great.

 

[karnalta]

Thank you Joeschmuck.

I think I will then go as I say in my first post, the only unanswered question is about the replacement of my two 500gb drives by two new 1To drives, but if it work like a traditional RAID it should be no problem. Drive replacement is normally one of the advantages of using a RAID system..

 

[joeschmuck]

I personally haven't made replacements in a RAID yet on FreeNAS but it is touted to work.

As for creating a RAID with the drives you specified, I completely agree with the advice you received from Bohs, mixing drives will not provide you what you desire. As I understand it when you create your ZFS RAIDZ you will be limited to the smallest hard drive size in your array, meaning you will only have 500GB from each drive, not the full 1.0TB from those two drives. Whatever the minimum size is, that is what you get. Also when you replace the two 500GB drives, I don't believe the upgrade is automatic and you will have to type in a few commands in the shell, which really won't be difficult because someone here would be able to tell you the proper command to type.

My best advice is to buy the 1TB drives up front and create your RAIDZ using all 4 drives of the same size. This may not be what you wanted to hear but unless you're just playing around right now with FreeNAS and don't mind destroying your data, that's the best advice I can give you.

-Mark

 

[karnalta]

I am currently playing around with FreeNAS and anyway I think I will have to buy the full stuff before being able to do my final NAS. Because my Asus P5Q Pro don't want to boot up automatically from FreeNAS, I have to always press F8 when booting to specific the HD where FreeNAS is installed. My USB thumb was't recognized too by my motherboard, I had to use an old hd to install FreeNAS.

But I still have one question, about processor. I actually have two possibilities to build up my nas system :
- Keeping my E8400 @ 3Ghz and buying a new mother board and a "medium" sized case.
- Buying a ITX mother board with an integrated processor and a nice small ITX case.

I prefer the second option except that I don't know which is the importance of the processor power for a NAS, the Intel E8400 will be far more powerful than a small Atom processor. But maybe processor power is obsolete for a NAS ?

 

[joeschmuck]

Odd how that motherboard is acting. I had one myself up until a few months ago, the board was RMA'd twice over a 1 year period for power issues so I tossed it.

A few things to consider... 1) try a newer USB flash drive, you can pick up a 4GB for dirt cheap these days and the new minimum requirements are 2GB. Many older drives are not bootable. 2) Did you setup the boot sequence in the BIOS properly?

I bought a new MB for my E8500 and I'm happy with it. Yes, I bought it with FreeNAS exclusively in mind. If I was to buy a new CPU as well, I would have done more detective work looking for a CPU that draws less power but was still very capable for my needs. You know, NewEgg has many sales where they sale a MB, CPU, and RAM for cheap, that could be a cheaper option, well maybe. You would have to hold out to a good deal but this weekend could be the time.

As an added note: My system draws 65 watts at idle (drives spinning), 45 watts idle (drives not spinning), and around 75 - 80 watts running hard. I can lower that by lowering the CPU frequency but right now I'm working to keep it stable. Also, I'm not recommending my MB, it's good if you leave things at pretty much default levels but underclocking is a real pain while keeping the system stable.

 

[karnalta]

All is set right in BIOS (I think so), the USB thumb I tried was a Corser Voyager 8Gb, my current USB thumb is correctly detected but I won't waste my Corsair Voyager GTR 32Gb for a NAS ^^

I will buy a cheap 2 or 4 gb thumb with my nas component anyway. My current deal is to choose between classic PC like a Core2Duo on a micro ATX board or a a low power consumption Atom system. But I am a bit afraid that ZFS Raid may require a bit too much CPU power than a Atom can provide..

 

[Bohs Hansen]

you might want to consider a E350 Zacate instead of an Atom cause of the Atoms chipsets 4gb ram limit. If you want a little more power but still stay in that area, check out the AMD NeoII

 

[karnalta]

Yeah that's the one I was thinking of, because I can put 8gb of RAM on it, and the E-350 has better benchmark result that the Atom. But I don't know if it will enough anyway.

 

[joeschmuck]

Stop making me jealous ! :( I want 8GB of RAM as well and a more efficient system.

 

[karnalta]

Ok I did my orders :p

I go with the AMD E350, I found an Asus motherboard with 5 SATA 6gb port and 8gb DDR3 support. I really wanted to have something with a low power consumption and fitting in a nice and really small case (Lian Li PC-Q08B). I hope performance will be good enough for my needs.

Thank you for all your help.

 

[Bohs Hansen]

I'm very happy with my E350 choice for my NAS system, in my initial tests with 8.0release I got around 65-70mb/s over CIFS without any tweaks on a 4disk raidz1 setup.

I'm sure you already found the E350 thread in the hardware section here. :)

 

[joeschmuck]

@ Bohs,
Do you recall the CPU usage during your speed transfer tests? I'm curious if the CPU was the limiting factor on your speed transfer.

 

[Bohs Hansen]

not during that test specific, but it was never above 30-40% according to my stats.

 

[joeschmuck]

That's good to hear. Did you try to saturate the 1Gbit interface from more than one location? I was able to get up to 97% saturation but I had to transfer files to the NAS from a SSD, a normal Hard Drive, and another NAS. My FreeNAS box is capable to handle that for over several hours without a single issue. I don't recall what my CPU was doing, that was many software builds ago. I'm just thinking you could get more throughput if you threw more at it.