Re: Identifying number of hardware devices involved from multipath

Posted by ErmanArslansOracleBlog on Aug 30, 2021; 8:06am
URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/Identifying-number-of-hardware-devices-involved-from-multipath-tp10182p10187.html

Yes. Sort of..
There is unique identifier of the device there -> 360002ac0000000000000006b0001c9fc
So you can use that id on the storage side and understand..
It seems storage is a 3PAR

Those scsi ids are telling you the following info ->

The first one , the host bus adapter (HBA) number

Second; The value for channel is the SCSI bus address.

Third, the value for Id is the target ID.

Last one , the value for Lun is the SCSI LUN.

For instance;  2:0:0:24  -> HBA 2, Channel 0, target ID 0 and Lun 24..

So, as you see in the output that you have sent; one Disk ( a storage disk probably) is seen from 4 paths.. 2 of them are based from HBA 1, and 2 of them are based on HBA 2.. They also differ in the target ids.. Linux sees the disk as 4 different disks.. This is normal and expected.. You will however; use the actual device name according to your multipath conf.. (not! the ones named with the scsi disk prefix sdc, sdec etc..)