Chassis recommendation

[Raphaël Bleuse]

Hello, there.

I am getting together the parts to build a FreeNAS. I've read the hardware commendations and by what I've seen, the chassis in picture seems to be good.

The only problem I see is cooling. I have no idea if the absence of several fans behind the disks is a problem or not. What do you think?

Initially I plan to install 8 disks at the most, so maybe I can keep some space between the disks since this case is for 20 disks total.

Thanks in advance for the help.

 

[Ericloewe]

I have no idea what chassis that is, but it's clearly lacking fans and will cook your drives. Got a model number?

 

[Raphaël Bleuse]

Got a model number?

Sure, the model in the picture is a Logic Case, ref. SC4320S.

 

[Ericloewe]

It's a dubious case (but it does have more fans than pictured).

The included fans are absolutely puny and will not be sufficient to cool the drives. This is basically bottom of the barrel rackmount stuff.

 

[Raphaël Bleuse]

Got your point. What brought me to this case is the fact that I do have rough constraints on depth.
The system I am willing to build has to fit in a <21" depth. Finding room for a microATX motherboard + hot swappable trays in front of the case seems difficult with such constraints.
Any advices?

 

[rogerh]

Got your point. What brought me to this case is the fact that I do have rough constraints on depth.
The system I am willing to build has to fit in a <21" depth. Finding room for a microATX motherboard + hot swappable trays in front of the case seems difficult with such constraints.
Any advices?

Apparently (I am no expert but have noted others' comments) hot swappability is a bit dubious on FreeNAS. If drives are only going to fail every year or two, having to take the chassis out of the rack as well as reboot is not an enormous penalty. (Of course, if downtime is costing you serious money or reputation you need to be spending five times as much on chassis!)

 

[jgreco]

Two fans? No fan bulkhead? Disk toaster.

Hot swapping works fine as long as the underlying hardware is correct. Lots of PC hardware doesn't bother to do this right because the average PC user does not disconnect and reconnect drives on a running system, for obvious reasons.

 

[rogerh]

Wouldn't it be true to say one has to think very clearly and carry out exactly the right operations in exactly the right order to safely hot-swap drives on FreeNAS? Maybe routine for a professional system administrator, but not everyone does this well.

 

[jgreco]

Wouldn't it be true to say one has to think very clearly and carry out exactly the right operations in exactly the right order to safely hot-swap drives on FreeNAS? Maybe routine for a professional system administrator, but not every one does this well.

"Click latch on hotswap bay, slide drive out just enough to power down drive, wait for spindown. Pull tray. Insert new tray with new drive."

It's not supposed to be difficult.

 

[Raphaël Bleuse]

Ok, your explanations explain why most of the chassis are at least 23" deep. Putting the disks in front of the case and the motherboard behind them needs more space than I expected.

My concern is that I have a setup with a very strict depth constraint (namely the chassis has to be 21" at most) while I do have some available Us (namely I can spend something like 6U).
Have you ever encountered chassis where the motherboard is located above/below the disk, allowing the chassis to be shallower?
Or do you think building my NAS in 2 parts (disks in one box, motherboard in another) is doable and does not add too much complexity?

 

[jgreco]

If you can find a suitable enclosure for your disks, you can build it in two parts, but this introduces new failure issues - what happens when the drive array's power supply fails, without also killing the head unit?

Generally, rack chassis manufacturers are looking to optimize for U, not depth, because that's the way it is usually needed to be optimized. Depth isn't usually a major issue.

 

[Bidule0hm]

Why there isn't a interlocking relay for multi-PSUs systems? it's very simple to do and cost nearly nothing. I just don't get it when you don't have this kind of thing despite the price of the thing...

 

[jgreco]

There is; look at the power control module for the Supermicro JBOD's.

 

[Bidule0hm]

Ah :) this is a good news (mainly for the OP) :)²

 

[Raphaël Bleuse]

Thanks for pointing out this issues and some possible solutions. What I don't see is why I cannot use only one PSU to power the whole thing.

@jgreco, by power control module, do you mean something like the CSE-PTJBOD-CB2 power card?
@Bidule0hm, what does mean the 'suspended disk cage' you have in your signature?

 

[jgreco]

Because a power supply is typically designed to support the goop within a chassis, not the goop within other chassis. They're usually sized to be able to handle the load. How would you handle the cabling, etc.? How many other chassis would you expect to be able to support? Etc.

 

[Bidule0hm]

@Bidule0hm, what does mean the 'suspended disk cage' you have in your signature?

Before any complain by other members about the vibrations and co: I know what I'm doing and I've some very restrictive noise constraints.

It means that I have the disks in a cage that is suspended by springs inside another cage. Here's a picture:

Actually I use steel cables + springs because I don't have the right springs on hand but I think you understand the idea ;)

You can see more about the case in this post: https://forums.freenas.org/index.ph...-ipmiutil-or-feeipmi.18377/page-6#post-178419 :)

 

[andrewjs18]

I have the rosewill RSV-L4500 4u case and love it. comes with 8 internal fans and 15 hdd bays...plenty of space for my purposes and it's relatively quiet considering how many fans the chassis has.

http://www.newegg.com/Product/Product.aspx?Item=N82E16811147164

I think I have some photos during my build. I'll have to look around for them tonight to post them in here if I find them.

 

[andrewjs18]

I also wanted to mention that the Rosewill case I have fits perfectly in a lack rack I built using lack tables from ikea...for about $30-40 bucks, I built a pretty nice rack shelf with a top shelf for a keyboard and monitor if I need to be in front of the server.

edited to add a link to my lack rack: https://forums.freenas.org/index.php?threads/home-user-racks.24264/page-2#post-149626