SOLVED How does an enclosure "know" which disk drive is which?

[Patrick M. Hausen]

Hi everyone,

I run this Supermicro chassis:

SC721TQ-250B | Mini-tower | Chassis | Products | Super Micro Computer, Inc.

721TQ-250B

www.supermicro.com

With this mainboard:

X10SDV-4C-TLN4F | Motherboards | Products | Super Micro Computer, Inc.

X10S, X10SD, X10SDV, X10SDV-4C-TLN4F

www.supermicro.com

Now as you can see in the picture the drive trays are neatly labeled and the individual bays are connected to SATA connector 0 to 3 on the board. Consequently the disk drives are ada0 to ada3.

When I do something like dd if=/dev/ada0 of=/dev/null I can easily identify the drive and so I know the trays match the logical numbering of the drives.

An then I learned about sesutil ...

When I do e.g. sesutil locate ada0 on the wrong trays are lit. The wrong way round. ada0 for what should be ada3, ada1 for ada2. So I am wondering if I just need to switch the on-board connectors? How does the device know which disk is in which tray, anyway? Is this just hardwired for a small system like mine?

Equally confusing:

Code:

root@freenas-pmh[~]# sesutil map  
ses0:
    Enclosure Name: AHCI SGPIO Enclosure 2.00
    Enclosure ID: 3061686369656d30
    Element 0, Type: Array Device Slot
        Status: Unsupported (0x00 0x00 0x00 0x00)
        Description: Drive Slots
    Element 1, Type: Array Device Slot
        Status: OK (0x01 0x00 0x00 0x00)
        Description: Slot 00
        Device Names: ada0,pass0
    Element 2, Type: Array Device Slot
        Status: OK (0x01 0x00 0x00 0x00)
        Description: Slot 01
        Device Names: ada1,pass1
    Element 3, Type: Array Device Slot
        Status: OK (0x01 0x00 0x00 0x00)
        Description: Slot 02
        Device Names: ada2,pass2
    Element 4, Type: Array Device Slot
        Status: OK (0x01 0x00 0x00 0x00)
        Description: Slot 03
        Device Names: ada3,pass3
    Element 5, Type: Array Device Slot
        Status: OK (0x01 0x00 0x00 0x00)
        Description: Slot 04
        Device Names: ada4,pass4
    Element 6, Type: Array Device Slot
        Status: OK (0x01 0x00 0x00 0x00)
        Description: Slot 05
        Device Names: ada5,pass5

Why are elements 5 and 6 in there? These are my SSDs that build the VM pool. They are not in the drive cage or in removable trays at all. So again - how does this "ses" thingy get an idea about which is which?

Thanks,
Patrick

 

[jrfrancisco712]

I think you have the trays in the wrong spots if you want it to match the backplane slot numbers. The manual shows that SAS #0 is on bottom and SAS #3 is on top.

 

[Patrick M. Hausen]

So it's hardwired and I am supposed to connect the matching SATA ports on the MB.

Thanks.