How to add a new SCSI LUN while server is Live
REDHAT/CENTOS:
In order to get wwn ids from a server:
• cat /sys/class/scsi_host/host0/device/fc_host\:host0/port_name
• cat /sys/class/scsi_host/host1/device/fc_host\:host1/port_name
Or:
• systool -av -cfc_host | grep port_name | awk ‘{ print $3 }’ | cut -d\” -f 2 | cut -dx -f 2
1.To add a new SAN LUN while live:
Run this to find the new disks after you have added them to your VM
• rescan-scsi-bus.sh
Note: rescan-scsi-bus.sh is part of the sg3-utils package
2.Check that it has been found, will be mpath(something)
• multipath –l
# That’s it, unless you want to fix the name from mpath(something) to something else
1.Change the shortcut name
• vi /etc/multipath_bindings
2.Remove the default mpath device autogenerated
• multipath –f mpath(something)
# Go into the multipath consolde and re add the multipath device with your new shortcut name (nickdsk2 in this case)
• multipathd –k
• add map nickdsk2
Note: Not going to lie, sometimes you could do all this and still need a reboot, majority of the time this should work. But what do i know…haha