>In addition verifying the size and stuff it could also check that the >paths really (still) point to the same device (by storing the LUN WWN in >the hw_handler context, for example) Just to eliminate any ambiguity here, using terminology from the standards: A LUN is a logical unit number. A WWN is a fibre channel port or node name. There's no such thing as a LUN WWN. I presume you mean to check the logical unit device identifier, which is the world wide unique and persistent identifier of a logical unit. (That's what you get (among other things) from Page 0x83 of the SCSI VPD read from the LU).