Supermicro SAS-826A backplane drive slot to SAS cable assignment?

[mrmikee]

Looking over the BPN-SAS-826A User Guide, I can not find any reference to which drive slot is wired to which SAS cable port. As this is a direct connect back plane, a drive to cable map or an assignment table would have been nice to have.

In other words if I'm only adding 4 drives to the chassis for now connected via JSM1 which of the 12 chassis drive slots are served by that SAS cable, and which are served by the other two?

 

[i386]

JSM1 = SAS In #1 = port 0-3
JSM2 = SAS in #2 = port 4-7
JSM3 = SAS in #3 = port 8-11

 

[nabsltd]

If you can't read the drive numbers on the backplane, Supermicro uses a "bottom to top, left to right" numbering.

So, JSM1 would use the bays in the first column, and the bottom bay in the second column.

 

[mrmikee]

JSM1 = SAS In #1 = port 0-3
JSM2 = SAS in #2 = port 4-7
JSM3 = SAS in #3 = port 8-11

Thank you, that confirms my time spent plugging and unplugging a single drive into all the ports with only one cable connected at a time. (Brute force research... LOL) Now I need to learn how Linux associates the hardware port to the "/dev/sdb" device so when a drive fails I know which port/bay the drive is in.

 

[nabsltd]

Now I need to learn how Linux associates the hardware port to the "/dev/sdb" device so when a drive fails I know which port/bay the drive is in.

It's not deterministic. /dev/sdb could move around between boots.

Persistent block device naming - ArchWiki

wiki.archlinux.org

 

[mattventura]

Thank you, that confirms my time spent plugging and unplugging a single drive into all the ports with only one cable connected at a time. (Brute force research... LOL) Now I need to learn how Linux associates the hardware port to the "/dev/sdb" device so when a drive fails I know which port/bay the drive is in.

The backplane supports management. Assuming your HBA supports it, install ledmon, and run `ledctl locate=/dev/sdb`

 

[nexox]

If you don't get the LEDs working, label each tray with the serial number of the drive inside, you might have to do some process of elimination if you can only read the serial numbers of the working drives, but you'll be able to pull the correct tray. You can also use the serial number to find the device file for a drive by matching it to a symlink in /dev/disk/by-id/.

 

[mrmikee]

The backplane supports management. Assuming your HBA supports it, install ledmon, and run `ledctl locate=/dev/sdb`

Thank you mattventura! This was exactly what I was looking for. It does work with my LSI SAS2308 HBA.