commit 6a9f9c9b449b19a8aedc2ab893f0754d4b87c95f
parent 347edc430c1e974a36098561cc908c32f3c8d42a
Author: MikoĊaj Lenczewski <mikolaj@lenczewski.org>
Date: Sat, 22 Aug 2026 17:25:05 +0100
Update README
Diffstat:
| M | README | | | 43 | +++++++++++++++++++++++++++++-------------- |
1 file changed, 29 insertions(+), 14 deletions(-)
diff --git a/README b/README
@@ -23,16 +23,33 @@ jbod: Design Notes
==============================================================================
Some notes, in no particular order:
-- The chassis is a 4U enclosure for 19-inch racks, and is 800 mm deep
- + The chassis will support standard 31-inch rack rails
+- The chassis is designed for "standard" 19-inch wide, 1000mm deep server racks
+ + The maximum width of a chassis in such a rack is 480mm
+ + The maximum depth of a chassis in such a rack is 900mm
+ + Heavy duty (<=200kg) slide rails will be around 0.75-inches wide per rail
+ + The maximum width of a chassis with rails is thus 17.5 inches
+ + The max. reasonable width for a chassis in such a rack is 17.5", or 440mm
+ + The max. reasonable height for a chassis in such a rack is 4U, or 177mm
-- The chassis front panel will be a dust-filtered mesh, with rack handles
- + The front panel grille will be a 3D printed design
- + The dust filter will be an existing stamped part
- + No drives are accessible via the front panel
+- The chassis has the following dimensions:
+ + Front panel dimensions (w/h/d 482/177/2.5 mm)
+ + Enclosure dimensions (w/h/l 440/177/800 mm)
+ + The chassis will support heavy duty (<=200kg) rack rails
+ - https://www.jonathanengr.com/product/432-433-series/
+
+- The chassis front panel will be a stamped mesh, with rack handles
+ + The front panel grille will be a stamped mesh
+ + The front panel will have two substantial rack handles
+ + The front panel will have LEDs shoing the status of each drive
+ + The front panel will have debug IO for the motherboard via USB-C
- The chassis will have a tool-less top panel
+- The chassis rear panel will contain solely PSU access, serial access, and IO
+ + The rear panel has meshes for exhaust airflow
+ + The rear panel allows access to the redundant 1+1 M-CRPS PSUs
+ + The rear panel allows serial access over both DB9 and RJ45 (exclusive?)
+
- The chassis has a two-chambered design for separate airflow regions
+ One chamber is solely for the 3.5-inch disks, with 6x push-pull fans
+ One chamber is for the PSUs, expanders, and motherboard, with 1x pull fan
@@ -40,25 +57,23 @@ Some notes, in no particular order:
- https://www.noctua.at/en/products/nf-a14-industrialppc-2000-pwm/specifications
+ Noctua 120mm industrial 2000rpm pwm fans (w/h/l 120/120/25 mm)
- https://www.noctua.at/en/products/nf-f12-industrialppc-2000-pwm/specifications
- + Noctua 80mm chomax swap pwm fans (w/h/l 80/80/25 mm)
+ + Noctua 80mm chromax swap pwm fans (w/h/l 80/80/25 mm)
- https://www.noctua.at/en/products/nf-a8-pwm-chromax-black-swap#hero
-- The chassis has dimensions w/h/l 482/177/800 mm
- + Front panel dimensions (w/h/d 482/177/2.5 mm)
- + Enclosure dimensions (w/h/l 434/177/800 mm)
-
- The chassis supports redundant 1+1 CRPS 1000W+ PSUs
+ Open Compute M-CRPS form factor standard PSUs (w/h/l 75/40/185+11 mm)
- https://www.opencompute.org/documents/m-crps-r1-v1p0-rc4-pdf
+- The chassis holds 72x 3.5-inch disks in a 6x12 configuration
+ + 3.5-inch disk dimensions (w/h/d 101.6/26.11/146.05 mm)
+ + 3.5-inch disk w/ caddy dimensions (w/h/d 105/30/150 mm)
+
- The chassis supports up to 2x SAS4 expanders, with multipath to all disks
+ The chassis has a 1x4 sff-8674 external port per expander
- https://members.snia.org/document/dl/25967
+ Each expander is connected to each disk for SAS multipath
-- The chassis holds 72x 3.5-inch disks in a 6x12 configuration
- + 3.5-inch disk dimensions (w/h/l 105/30/150 mm)
- + Drives are in groups of 4, with 4 U.3 connectors per backplane
+- Drives are in groups of 4, with 4 U.3 connectors per backplane
+ Backplanes have a single sff-8654 8i U10 connector per backplane
- Each drive is connected in a x1 configuration to each expander
- Each drive can be connected to up to 2 expanders
