Was it a simple swap SAS for SAS, SATA for SATA, connecting to the same flexbay?

@Chino de Oro​ hi, thanks for your reply. Yes, I tried the 2.5" sata disks in pair on several flex bays

@saturn0​ , I meant connecting the SSD to the same connectors of the two working HDD for testing.  There are a total of 4 drives spaces in two flexbay and none is working in yours case?

Remember that the default profile does not change when you connecting different drives types until reboot for profiles change.

@Chino de Oro I have tried all 4 flex bats available but it did not work.

I even tried to connect them directly to the controller. 

is there such a thing called channel firmware that could cause problems?

Since you already have had two working HDD, there is no need to check for anything else.  Just remove the HDD and install the SSD in its places.  What is the model of the HDD and SSD you are using?

Did you access Device Configurations at boot or using Controller Management Application?  If you are concerning about firmware issue, you can update firmware, driver, and running the application to see if it can detect the drives.

LSI MegaRAID SAS 9440-8i and 9460-16i Controller driver 

LSI MegaRAID SAS 9440-8i Controller firmware.

LSI MegaRAID 9440-8i and 9460-16i Controller Management application

Hi @Chino de Oro 

I have put 2 spinning disks in the flexbays and are detected in the raid manager. Even if I try a single disk is being detected. One disk is 500GB and the other is 1 TB from the same brand: HGST (Hitachi).

Then, I have replaced them with 2 SSD both Crucial of 1 and 2 TB, and they were not detected by the raid controller like the spinning disks. In the past, I have also tried with a Samsung EVO and a Crucial, with the same unsuccessful result.

None of the SSD and spinning disks are visible in the BIOS as the flexbays connect directly to the raid controller. 

BIOS is currently configured to support AHCI SATA operation with UEFI with legacy boot disabled ( I have tested this latter also in enabled mode).

I have taken pictures, if they can help. Any help is greatly appreciated! Thanks

Hi again, I connected the ssd to the SATA connector on the motherboard (bypassing the raid controller), I stalled windows 10 and installed the controller driver and the management application. The firmware did not need an upgrade. I have not tested yet the software, but I can confirm that I am still experiencing the same issue, where only spinning disks are detected when connected to the raid controller.

I have checked the storage part available

for my server on the Dell shop and the only available SSDs are from a brand called Origin:  

https://www.dell.com/en-uk/shop/origin-storage-25in-2tb-sata-class-20-3d-tlc-ssd/apd/ab976141/storage-drives-media

Do you think that the hardware is limited?

After swapping out HDD for SSD, reboot the system one more time to get profile change before accessing the controller interface for volume setup.

@Chino de Oro  hi, apologies for the slow reply.  I have tried several times but the SSD are not still seen in the Device Configuration at boot.

However, when I swap SSD for HDD, the disk are seen on the first boot.

hi again @Chino de Oro, I was googline when by accident I have found the compatibility list of HHD and SSD drives. Based on your experience, do you know other users who successfully used SSD not listed in here?

https://techdocs.broadcom.com/us/en/storage-and-ethernet-connectivity/adapter/megaraid-94xx-tri-mode-compatibility/1-0/v13154213.html

I do not think the brands was the issue.  The brand of your SSD should be compatible with Dell machines and its storage controllers.

At some points, similar issue was turned out to be the connection.  Be certain that the 2.5" adapter bracket being set properly when inserting in the flexbay. 

@Chino de Oro  great news!

The list of compatible disks does not list Crucial brand.

Therefore, I have re-tested the Samsung SSD and it worked fine. Not sure why was not seen on my previous test. I have now bought 2x Samsung SSD and will put them in raid.

Thank you very much for your assistance!!!

Glad to help out.