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Mounting a disk persistently on your saltbox server

Perhaps you want to mount a disk partition persistently in the file system like a media drive at /mnt/local/Media or a fast SSD for Usenet at /mnt/local/downloads.

Gathering details

First, find out the device reference:

lsblk

this will display something like: 

/srv/git/saltbox$ lsblk
NAME                 MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda                    8:0    0 12.7T  0 disk
└─sda1                 8:1    0 12.7T  0 part
sr0                   11:0    1 1024M  0 rom
nvme0n1              259:0    0  1.8T  0 disk
├─nvme0n1p1          259:1    0  512M  0 part /boot/efi
├─nvme0n1p2          259:2    0    1G  0 part /boot
└─nvme0n1p3          259:3    0  1.8T  0 part
  └─ubuntu--vg-lv--0 253:0    0  1.8T  0 lvm  /
I want to mount that 12.7T partition, sda1.

Now let's get the UUID of that partition:

sudo blkid

That will display something like: 

/srv/git/saltbox$ sudo blkid
[sudo] password for seed:
/dev/nvme0n1p3: UUID="Br73Mj-1hiQ-DpPX-7rwb-Q2E1-4Rdb-HQBezw" TYPE="LVM2_member" PARTUUID="a5ed9aed-da7f-43ad-b1a2-c9b35017e00a"
/dev/nvme0n1p1: UUID="5524-9590" BLOCK_SIZE="512" TYPE="vfat" PARTUUID="af869940-c4de-4562-844d-2a46bd8c5680"
/dev/nvme0n1p2: UUID="ecc24163-8465-4983-9676-7d85f9cdb31a" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="aff553a3-ad14-4d7c-8e08-7c6d87e59429"
/dev/mapper/ubuntu--vg-lv--0: UUID="1956420b-8d19-4573-abdf-10126ede727c" BLOCK_SIZE="4096" TYPE="ext4"
/dev/sda1: UUID="9d4c3257-8e05-4228-b970-15ddbc99e86f" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="cf6ca88f-498f-3f41-86bd-e891de24466c"

We can see the UUID and filesystem of that device in the table:

/dev/sda1: 
UUID="9d4c3257-8e05-4228-b970-15ddbc99e86f" 
...
TYPE="ext4"
...

Editing fstab file for persistent mount.

Now you need to edit the fstab file, which controls what gets mounted at system startup.

sudo nano /etc/fstab

You want to add a line to the bottom of that file. Don't edit anything in the file already.

In my case, I want to mount that 12.7T partition at /mnt/hdd.

The line you need to add should look something like this (details may differ):

/dev/disk/by-uuid/9d4c3257-8e05-4228-b970-15ddbc99e86f /mnt/hdd ext4 defaults  0      2
                  |                                    |        └ format from blkid output
                  |                                    └ directory where you want to mount this partition
                  └ UUID from blkid output

In my case, /etc/fstab starts looking like this:

/srv/git/saltbox$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/ubuntu-vg/lv-0 during curtin installation
/dev/disk/by-id/dm-uuid-LVM-087oBvV8gi2gDtJZBPmc0owcPXPdkpzTdwtdNt8jU3SNavox61p3nyq1gfaIRzz0 / ext4 defaults 0 1
# /boot was on /dev/nvme0n1p2 during curtin installation
/dev/disk/by-uuid/ecc24163-8465-4983-9676-7d85f9cdb31a /boot ext4 defaults 0 1
# /boot/efi was on /dev/nvme0n1p1 during curtin installation
/dev/disk/by-uuid/5524-9590 /boot/efi vfat defaults 0 1
/swap.img   none    swap    sw  0   0

And I add one line at the end so it looks like this: 

/srv/git/saltbox$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/ubuntu-vg/lv-0 during curtin installation
/dev/disk/by-id/dm-uuid-LVM-087oBvV8gi2gDtJZBPmc0owcPXPdkpzTdwtdNt8jU3SNavox61p3nyq1gfaIRzz0 / ext4 defaults 0 1
# /boot was on /dev/nvme0n1p2 during curtin installation
/dev/disk/by-uuid/ecc24163-8465-4983-9676-7d85f9cdb31a /boot ext4 defaults 0 1
# /boot/efi was on /dev/nvme0n1p1 during curtin installation
/dev/disk/by-uuid/5524-9590 /boot/efi vfat defaults 0 1
/swap.img   none    swap    sw  0   0
/dev/disk/by-uuid/9d4c3257-8e05-4228-b970-15ddbc99e86f /mnt/hdd ext4 defaults  0      2

Then save the file.

Now go create the directory and set the ownership:

/srv/git/saltbox$ sudo mkdir /mnt/hdd
/srv/git/saltbox$ sudo chown -R seed:seed /mnt/hdd
[assuming you are using the saltbox default seed user]

Then mount the partition: 

/srv/git/saltbox$ sudo mount -a

That command produces no output if it succeeds.

You can verify that the disk was mounted with df:

/srv/git/saltbox$ df -h

/srv/git/saltbox$ df -h
Filesystem                    Size  Used Avail Use% Mounted on
tmpfs                         1.6G  1.7M  1.6G   1% /run
/dev/mapper/ubuntu--vg-lv--0  1.8T  8.5G  1.7T   1% /
tmpfs                         7.8G     0  7.8G   0% /dev/shm
tmpfs                         5.0M     0  5.0M   0% /run/lock
/dev/nvme0n1p2                974M  224M  683M  25% /boot
/dev/nvme0n1p1                511M  6.1M  505M   2% /boot/efi
tmpfs                         1.6G  4.0K  1.6G   1% /run/user/1000
/dev/sda1                      13T   11T  1.4T  89% /mnt/hdd

There it is at the end of the list.

That partition will now be mounted there at system startup automatically.

If you compare the lsblk output now to what it was:

/srv/git/saltbox$ lsblk
NAME                 MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda                    8:0    0 12.7T  0 disk
└─sda1                 8:1    0 12.7T  0 part /mnt/hdd
sr0                   11:0    1 1024M  0 rom
nvme0n1              259:0    0  1.8T  0 disk
├─nvme0n1p1          259:1    0  512M  0 part /boot/efi
├─nvme0n1p2          259:2    0    1G  0 part /boot
└─nvme0n1p3          259:3    0  1.8T  0 part
  └─ubuntu--vg-lv--0 253:0    0  1.8T  0 lvm  /

You can see that the sda1 device now has a mountpoint listed in the last column.