Editing Mounting iSCSI LUNs (section)

== Mounting the LUN ==
This is where things diverge for different Linux distributions.  The differences include the sequence during boot where multiple things have to happen before the mount is successful:
# the basic device structure is created
# the network devices are created
# the network devices are configured and connect to a network
# the iscsi subsystem starts and tries to connect to the storage server
# the mount process takes the device created by the iscsi session and mounts it

Getting these activities to happen in the right order is what gets challenging; the process for doing this under RHEL-style distributions uses systemd and is described [[Systemd mounted iSCSI volumes|here]].

With Debian-based distributions, the process only involves adding an entry to the '''''/etc/fstab''''' file.  First, however, you need to create the filesystem and get the needed data for mounting.  Get the device assigned to your LUN:

 ls -l /dev/disk/by-path

This will show all your drives -- the one for the LUN will actually contain the iqn for the LUN in the path.  Now you make the filesystem (I prefer XFS):

 sudo apt install -y xfsprogs
 sudo mkfs.xfs /dev/sdX

Now you get the UUID for the filesystem to create the entry in '''''/etc/fstab'''''.  Mounting by UUID is safer than using the device name since if you add more iSCSI LUNs or add other disk devices, the device name can change.

 ls -l /dev/disk/by-uuid

Find the UUID for the iSCSI device.  Note that this UUID is created by the ''mkfs'' process ... if you rebuild the filesystem, it will have a new UUID.  Now you can add a line to '''''/etc/fstab''''':

 UUID=<uuid from the last step> <mount point> xfs _netdev,auto,defaults	0 0

The ''_netdev'' specifies that the device is network-based and must wait for the network to be up and stable before the mount can succeed.  Now you can mount the device or just reboot the system:

 sudo mkdir <mount point> 
 sudo mount <mount point>

Definitely more work than it should have taken ...