iscsi-automount: A Shell repository from f1linux

VERSIONING & ATTRIBUTION

Script Author: Terrence Houlahan, Linux & Network Engineer F1Linux.com
Author Site: http://www.F1Linux.com
Script Version: 1.11.01
Script Date: 20220710

These scripts and others by the author can be found at:

https://github.com/f1linux

INTRO

These scripts automate- as much as reasonably possible- the grunt work of configuring an UBUNTU host to connect to an iSCSI disk on boot and then mount it.

The original use case for writing these scripts was for configuring Raspberry Pi's- the 8GB models- to run Docker applications on 64bit Ubuntu. Frequent writes to a Pi's MicroSD card will hammer it, so I wanted to load a chunk of iSCSI storage for operations requiring frequent writes. iSCSI doesn't write to the local filesystem.

Creating the required systemd service & systemd mount on a bunch of Pi's manually was just donkey work, so I automated the configuration. Anyhoo, these scripts are generally useful and with a (small) bit of tweaking could be adapted to enterprise use for any version of Linux using systemd; knock yourselves out.

What these (2) scripts DO:

config-iscsi-storage.sh:

Creates a systemd service connect-luns.service to connect the LUN on boot. It also checks to see that the open-iscsi package is installed as well as checking if the OS is Ubuntu

config-iscsi-storage-mounts.sh:

Creates systemd services mnt-logs.mount and mnt-logs.automount to mount the iscsi disk on boot in /mnt - consistent with FHS guidance. The automount service is additionally configured for the sake of completeness: it's not required as it's is actually for mounting on-demand whereas we just want to mount the external storage on boot.

What these (2) scripts DON'T do:

Partition the conected iSCSI disk
Format the iSCSI disk with a filesystem

COMPATIBILITY

These scripts were developed using Ubuntu 20.04 LTS and should just work out of the box with other versions of Ubuntu and other Debian derivatives.

Where RHEL or Red Hat derivatives are being used, some tweaking with the package management parts of the script will of course require modification.

But the Systemd stuff and anything which is straight bash should "just work" and be largely distribution independent.

INSTRUCTIONS

STEP 0: Create some LUNs on your storage box. Even a cheap Synology SoHo storage appliance can export LUNs. Configuring CHAP authentication on LUNs is highly recommended.
STEP 1: Image a Pi with Ubuntu
STEP 2: Download these scripts as your standard user- ie 'ubuntu'- into your home directory:
```
  git clone https://github.com/f1linux/iscsi-automount.git
  cd iscsi-automount
```
STEP 3: Set required values in "SET VARIABLES" section of config-iscsi-storage.sh and then execute it:
```
  sudo ./config-iscsi-storage.sh
```
STEP 4: Partition the iSCSI disk after it connects to the Linux host: ie, fdisk /dev/sdX where "X" is the letter of the iSCSI disk
STEP 5: Format the iSCSI disk with a filesystem: ie, mkfs.ext4 /dev/sdX1 where the iSCSI disk is /dev/sdX
STEP 6: Set required values in "SET VARIABLES" section of config-iscsi-storage-mounts.sh and then execute it:
```
  sudo ./config-iscsi-storage-mounts.sh
```
WARNING: Do NOT use a hyphen when specifying the folder name in the variable "ISCSIDISKMOUNTFOLDER" in "config-iscsi-storage-mounts.sh". A folder name with a hypen with cause the SystemD mount to fail.
STEP 7: Reboot and execute the mount command to verify that the iSCSI disk mounted on boot.

DEPENDENCIES

mnt-logs.mount: uses the "After=" directive creating a dependency on the connect-luns.service; if the LUN isn't connected, there's nothing to mount! So where the connect-luns.service fails, then the mnt-logs.mount service will also be broken.

mnt-logs.automount: This service relies on the mnt-logs.mount service to be correct. If it's not, then the mnt-logs.automount will of course fail. But the primary use case I wrote the scripts for was to automate bringing the LUN up on boot in our host & mounting it rather than mounting it conditionally when a process needed to write to it.

MANAGING SERVICES

To start or check the status of the custom systemd services created by these scripts:

sudo systemctl [start/status] connect-luns.service

sudo systemctl [start/status] mnt-logs.mount

sudo systemctl [start/status] mnt-logs.automount

LICENSE

These scripts are licensed under GPL 3.0.

f1linux/iscsi-automount