Server hardware, HBA, SAS expander, JBODs - wiki/how to

I thought it might be a good idea to start a general topic about all this server type hardware that is very useful and budget friendly for Chia plotting but is out of the comfort zone for most including myself.
But there are quite a few people here who know their way around this stuff so I;m sure this can get filled up.

I’m just going to start of with some general stuff, hopefully other can expand on that.

JBOD (Just a bunch of disks)
An enclosure that can hold an x number of harddrives, usually including a power supply and a controller with external mini-sas connectors.

HBA (Host Bus Adapter)
An pcie expansion card with internal and/or external connectors for storage solutions.
.e.g. a SAS HBA can have internal/external mini-sas ports to connect to either SAS drives directly or connect to a JBOD.
Mini SAS connectors support 4 lanes, meaning they can split to run 4 drives.

SFF-8088 / 8087
Older generation (SAS 2.0, 6Gbs per lane) Mini SAS connector, 8088 (external) 8087(internal)

SFF-8644 / 8643
Current generation (SAS 3.0 12 Gbs per lane) Mini SAS connector, 8644 (external) 8643 (internal)

SAS connectors
SAS connectors are the same as SATA connectors, a Sata drive can also be connected, but a SAS drive cannot be connected to a Sata port

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Couple of things I’ve learnt since my farm is nearly all SAS.

  • Very old SAS cards, like the LSI 3Gb/s models, work fine with SAS disks of any size, but if you put SATA disks on them > 2TB they will only show as 2TB disks.
  • Look out for cards that can be put into IT (initiator target) mode rather than hardware RAID mode, this usually requires flashing firmware on the card. If you don’t/can’t do this the hardware RAID controller jumps in front of the BIOS and slows boot, makes the disks difficult to use with other controllers, and is just generally more of a pain to work with, this applies even if you just make single-disk RAID 0s.
  • Also be aware when buying RAID controllers, some of them need cache modules that might be sold separately, sometimes even to run in HBA modes.
  • External connectors are a bit more expensive than internal connectors, but there’s only so much internal space you can use before needing… lets say ‘modifications’.
  • If you want to mix/match SAS/SATA, be aware that some of the cables are directional. E.g there are 2 types of cable that connect 4 SATA connectors to 1 SFF-8087 connector, one for connecting a SAS controller/mobo to disks, and one for connecting the SATA ports on a controller/mobo to a backplane, they both look the same, fit mechanically, but will not work if used for the wrong purpose.

Edit:

  • Also, RAID/SAS controllers get HOT, make sure they are in a case with good airflow like a server chassis with front->middle->rear fans, or do what’s needed to get airflow over the heatsinks.
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I used to use a perc6/ir in my dellt710. upgraded to a h200 with it mode firmware. for that —extra 3Gb/s in
— IT mode gives u freedom from outdated hardware raid controllers like the perc6.
with IT you can manage disks individually for jbod for deep storage of plots or any sort of software raid. in preferred hypervisor. or bare metal.
you can flash IT mode yourself or I highly recommend server parts from
https://www.artofserver.com/#services
spent a lot of money at his eBay store and his you tube videos are just full of that deep lost hba knowledge. jbods, nfs, hardware, its great. he og reason I got into servers than found chia.
t710 11 gen power edge
8x 4tb drive bays with dual 8087 backplane to h200
70tb in external hdds on usb 3.2 pcie card 4x
4x pcie nvme 500gb
dual 1000w redundant power supply
96gb ram
x2 x5690s
no complaints
30’ish/day plot.
on hardware that’s 10 years old
the servers are really where its at im finding. sweet spot for the money. I only paid 150 for the server itself.

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