iSCSI: no LUNs detected for session when using openfiler

A common problem...

If you are using openfiler, at some point of time, you are bound to reboot the openfiler OS/machine. After the reboot, a common problem is that openfiler forgets or loses the logical volume/volume group information.

So, as a workaround, you need to issue the following commands:

################################
# to discover the volume groups
################################
# vgscan   

#################################
# to discover the logical volumes
#################################
# lvscan  

##################################
# to discover the physical volumes
##################################
# pvscan

Then, you can display them using the commands vgdisplay, lvdisplay, pvdisplay. Similarly, there is a whole suite of commands in the same location.

Then, you STILL need to activate the discovered logical volumes using the -ay switch of lvchange:

# lvchange -ay openfiler/asm
# lvchange -ay openfiler/ocr
# lvchange -ay openfiler/vote

Now, if you run the lvscan or lvdisplay command, the status of the Logical volumes will show as ACTIVATED.

Remember..

AFTER you do this, You will STILL need to restart the iscsi-target service on openfiler machine.

openfiler $> service iscsi-target restart

If you fail to do this, you will see these messages in the dmesg output on the iscsi-initiator node (not the openfiler machine) - iSCSI: no LUNs detected for session. This message can be very confusing, especially since you will see that the session to the iscsi target WAS established:

openfiler $> dmesg
...
...
iSCSI: bus 0 target 0 = iqn.2006-01.com.openfiler:openfiler.vote
iSCSI: bus 0 target 0 portal 0 = address 10.143.213.248 port 3260 group 1
iSCSI: starting timer thread at 286340
iSCSI: bus 0 target 0 trying to establish session to portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 1 = iqn.2006-01.com.openfiler:openfiler.ocr
iSCSI: bus 0 target 1 portal 0 = address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 1 trying to establish session to portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 0 established session #1, portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 2 = iqn.2006-01.com.openfiler:openfiler.asm
iSCSI: bus 0 target 2 portal 0 = address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 1 established session #1, portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 2 trying to establish session to portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 3 = iqn.2006-01.com.openfiler:openfiler.test
iSCSI: bus 0 target 3 portal 0 = address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 3 trying to establish session to portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: bus 0 target 2 established session #1, portal 0, address 10.143.213.248 port 3260 group 1
iSCSI: no LUNs detected for session (bus 0 target 0) to iqn.2006-01.com.openfiler:openfiler.vote
iSCSI: no LUNs detected for session (bus 0 target 1) to iqn.2006-01.com.openfiler:openfiler.ocr
iSCSI: no LUNs detected for session (bus 0 target 2) to iqn.2006-01.com.openfiler:openfiler.asm
iSCSI: bus 0 target 3 established session #1, portal 0, address 10.143.213.248 port 3260 group 1