The Effect of Device Replacement on Agile Device Files

Figure 2: Multiple paths to a LUN

The following ioscan command output shows two lunpaths for disk1:

# ioscan –m lun /dev/rdisk/disk1

disk 1 64000/0xfa00/0xa esdisk CLAIMED DEVICE online HP

HSV210

0/1/0/0.0x0x500508b3009097f9.0x4001000000000000

0/1/0/0.0x0x500508b3009097f1.0x4001000000000000

/dev/disk/disk1 /dev/rdisk/disk1

In Figure 3, when an LU is replaced, the LU name to LUN mapping changes. This change is detected

by the storage stack, and results in access being blocked to the LU on all paths on which the change

of mapping is discovered. The lunpath state becomes authentication failed (AUTH_FAILED) and the

LU state becomes no hardware (NO_HW). The LU remains in this state until you validate the change

using the scsimgr replace_wwid command.