LSI 3008 based HBA (mpr) and backplane slot identification

[Alan Somers]

On Thu, Jun 4, 2015 at 5:08 AM, Borja Marcos <borjam at sarenet.es> wrote:
>
> Hello,
>
> I am now trying the LSI 3008 based HBAs, and I would like to know wether I have a _reliable_ slot identification method or not.
>
> I am using the sas3ircu tool in the same way I did with the LSI 2008 HBA. It helps me to locate the slot number for a disk
> using "sas3ircu 0 display".
>
> --------
> Device is a Hard disk
>   Enclosure #                             : 2
>   Slot #                                  : 16
>   SAS Address                             : 5005076-0-3ea6-f971
>   State                                   : Ready (RDY)
>   Size (in MB)/(in sectors)               : 953869/1953525167
>   Manufacturer                            : ATA
>   Model Number                            : Samsung SSD 840
>   Firmware Revision                       : CB6Q
>   Serial No                               : S1D9NSAFB14948X
>   GUID                                    : N/A
>   Protocol                                : SATA
>   Drive Type                              : SATA_SSD
> -------
>
> What I don't know is: can I consider this a reliable method of identification? Can these slot numbers be somewhat shuffled due to
> "cached" parameter oddities similar to the target ID persistance issues?
>
> In case we need to replace a disk we need to make sure we are using the right slot number.
>
> Besides, it would be a good idea to have a port with sas3ircu, the same way there is one for sas2ircu.
>
>
>
>
> Thanks!
>
>
>
>
>
> Borja.

I've never used sas3ircu or sas2ircu, but it's probably getting the
slot number based on either the expander's SES Additional Element
Status Page, or by the expander's SMP DISCOVER response.  Both of
those methods will give stable responses.  Even if you swap drives,
move them around, turn phys on and off, etc, both of those methods
will still map the same physical slot to the same Slot # every time.
Only an expander or HBA firmware upgrade can change it.  However, the
slot mapping may not make intuitive sense.  You'll have to experiment
to see what Slot # corresponds to what physical slot.

When you need to replace a drive, your best option would be to use the
"sas3ircu locate" command to turn on the slot's error LED.  Then you
won't need to consult a slot mapping diagram.

-Alan