3U, 12 bay, shortdepth chassis?

[lux]

I live in the UK. Is anyone aware of a 3U 12 bay shortdepth chassis?

I’m trying to transition from an 8Bay QNAP to a brand new 12bay unraid solution. But trying to find a shortdepth chassis is a nightmare. 

 

At this point, I’d even settle for an 8 bay shortdepth 2U.

 

My thoughts here is that I will have a separate 1U chassis as the application server (plex, radarr, sonarr, tidarr, overseerr, sabnzbd etc). I assuming also that the best way to connect all of this is via the switch (I’m reading things about SAS and backplanes).

[Vr2Io]

15 hours ago, lux said:

I assuming also that the best way to connect all of this is via the switch (I’m reading things about SAS and backplanes).

For connect disks, locally is the best, extend by SAS fine. Separate 2U to two 1U, then will limit to 4 disks x2 rather then 12 disks.

 

15 hours ago, lux said:

3U 12 bay

Must rack ? Why don't Tower.

[lux]

Basically I’ve no where to put it.

I have a small utility room, it houses a comms cabinet with my unifi router / switch, patch panel, PS5, Denon amp.

 

The utility room has a lot of human ‘traffic’ - it has the washing machine, tumble dryer, and is the route to the downstairs bath room. As such, I don’t want the tower on the floor where it could be kicked, hit by accident with the hoover, or otherwise by close the washing machine in case that breaks / floods.

 

Ideally I want a dumb 8 bay / 12 bay NAS, and then a separate 1u application server.

 

What I don’t understand is unraids approach to server expansion. If you have a 2U 8 bay NAS and want to expand, you have to ditch the whole thing and get a 3U. 
 

You can’t just buy a 1U ‘expansion’ server, and connect the 2 NAS together to form one storage pool.

[Vr2Io]

2 hours ago, lux said:

You can’t just buy a 1U ‘expansion’ server, and connect the 2 NAS together to form one storage pool.

You can, SAS can do that, put a SAS expander in a box ( as disk enclosure ) then connect to main server's SAS controller then all disks in two box still in local. All disk freely assign for array / cache pool / mount by UD etc.

[lux]

4 hours ago, Vr2Io said:

You can, SAS can do that, put a SAS expander in a box ( as disk enclosure ) then connect to main server's SAS controller then all disks in two box still in local. All disk freely assign for array / cache pool / mount by UD etc.

Oh wow. Yeah I absolutely missed that in my research.

 

Ok firstly thank you for sharing your knowledge, genuinely appreciate it. You e most likely saved me a huge amount of money and time, really appreciate you taking the time to respond to my posts.

 

If I may, a follow up question:

 

If I can’t find the chasis I need, I can get a 5 port HBA controller (one port for each disk) in a 1U chasis with 4 bays / disks, and then a cable goes to the expander in the next chasis.

 

But the next chasis does *not* require a controller, as it’s being controlled from the first chasis. Assuming the chasis is another 1U 4 bay, then all 4 disks will share the bandwidth of the single port from the controller.

 

Actually thinking / talking about all this out loud, I don’t need a 5 port controller do I? I can do a 2 port controller, as each port has a 6gb bandwidth, and if I only have 4 disks in a chassis with max 250mb/s read or write, then I won’t even come close to saturating the controller with 4 disks on one port. 

Edited August 4, 2021 by lux

[Vr2Io]

Take LSI 9211-8i for example ( 8i means internal x8 wide ), you will found physically have two SFF-8087 connector, people usually connect 4+4 disks. The bandwidth per single port is 6Gbps x4 = 24Gbps, but actual throughput was ~2GB/s.

 

For external enclosure purpose, people will use one port (HBA)  connect to a SAS expander then fan-out more and more port, the disk no. was depends on how many port provide by expander, and it will share the 2GB/s bandwidth.

 

But for external use case, people will buy HBA / Expander in dedicate connector, so you will got something like 4i4e or 8e ...... SFF-8087 SFF-8088 .... etc

 

Edited August 4, 2021 by Vr2Io