A few updates on my testing:
As there did not seem to be a cable problem, I swapped the Sata port 1 and 2 cables back to match the wiki build document. Note: the UPS battery is not connected.
I did attempt to downgrade the Seagate Barracuda SSD 120 1TB to 3.1 specifications. The downgrade failed on an error so that avenue has been abandoned.
I acquired a new Samsung SSD 860 EVO 1 TB hoping that it works better than the Cuda 120 SSD.
I retested 5 different drives on each Sata port. The drives were
WD RED 10TB #2 (two Red 10TB drives tested are labeled #2 and #3, just the number on the drive rail)
Samsung SSD 86 EVO - 1 TB
SanDisk Extreme II SSD - 240GB
Seagate Barracuda SSD 120 - 1TB
WD RED 10TB #3
For each Sata port, the a single drive was installed with a power on boot to determine whether the drive was visible/recognized after the kernel was started.
port 1: recognized: 2, 5 not recognized: 1, 3, 4
port 2: recognized: 1, 3 not recognized: 2, 4, 5
port 3: recognized: 1, 3 not recognized: 2, 4, 5
port 4: recognized: 1*, 2*, 3, 5 not recognized: 4
port 5: recognized: 1, 2, 3, 4, 5 not recognized:
* - very slow boot, many resets, recognized at 3.0Gbps
An observation: during the u-boot process there is a pause just after "Net: eth0: ethernet@fe300000" and before "scanning bus for devices..." of about 10-12 seconds With a drive installed in Sata ports 3, 4, 5, front panel LED lights up almost immediately after "Net: eth0: ethernet@fe300000" is displayed. If the LED is not on, the drive will not be recognized. On Sata port 1 and 2, there is a 10-12 second pause after "Net: eth0: ethernet@fe300000" is displayed and then the bus scan. I'm assuming this is a staggered power start up, Sata ports 3, 4, 5 and then Sata port 1, 2. Just visually, it seemed more random on port 1 or 2 whether a device has time to complete power up before the bus scan.
I'm looking for a 3 drive configuration; a 1 TB SSD with the two WD RED 10 TB HDD. As the Cuda SSD 120 only seems to be recognized in port 5, I'll proceed with the Samsung SSD 860 EVO. But what ports? Ports 4 and 5 seem the most reliable so I'm putting the HDDs on these ports. My preference was to have the SSD on port 1 but I did experience a couple of times where the SSD wasn't recognized in this 3 drive configuration. So, I'm testing with the SSD on port 3 and the HDDs on port 4 and 5. So far, this is looking to be the best configuration. It's odd that the SSD was not recognized on port 3 during the single drive tests but seems stable with three drives.
Jim