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CachyOS

Automount Additional Drives Through fstab at Boot

This tutorial will describe the basics of utilizing the fstab file located in /etc/ in order to mount static drives during boot. It will briefly explain how to find a partition or drive’s UUID, what some options do, and further reading should the information provided be insufficient.

Prerequisites

  • Root access

Adding Entries to /etc/fstab

1. List the UUIDs of your partitions

In the terminal emulator of your choice (Konsole, Alacritty, Kitty, etc.) run the following:

Terminal window
❯ lsblk -f
NAME        FSTYPE FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
zram0                                                                              [SWAP]
nvme0n1
├─nvme0n1p1 vfat   FAT32       E04D-9F05
├─nvme0n1p2
├─nvme0n1p3 ntfs               08A24E90A24E81E4                      715.4G    50%
├─nvme0n1p4 vfat   FAT32       E09C-D4DA                             628.1M    39% /boot
├─nvme0n1p5 ext4   1.0         187a9f06-9411-48d9-b941-f03c2e605812  203.6G    47% /
└─nvme0n1p6 ntfs

In our example, we know that we want to mount a Windows partition, which is ntfs, and we know that roughly half its space is available. Thus we can determine that the partition we want to mount is nvme0n1p3 and its UUID to be 08A24E90A24E81E4, with a file system of ntfs in this example.

2. Identifying your partition

Often lsblk -f will provide all the information you need to mount your disk through /etc/fstab at this point. Should you find the information lacking however you can run the following:

Terminal window
❯ sudo fdisk -l
Device              Start        End    Sectors  Size Type
/dev/nvme0n1p1       2048     206847     204800  100M EFI System
/dev/nvme0n1p2     206848     239615      32768   16M Microsoft reserved
/dev/nvme0n1p3     239616 2997384182 2997144567  1.4T Microsoft basic data
/dev/nvme0n1p4 2997385216 2999482367    2097152    1G EFI System
/dev/nvme0n1p5 2999482368 3905454079  905971712  432G Linux root (x86-64)
/dev/nvme0n1p6 3905454080 3907026943    1572864  768M Windows recovery environment

We already know our UUID in this example, however, fdisk -l can make it a bit more clear to us by showing the exact size of the partition (1.4T) as well as its type (Microsoft basic data)

That should make it abundantly clear to us that the partition we want is nvme0n1p3 with a UUID of 08A24E90A24E81E4 as described earlier. We knew earlier, but now we just know it for sure.

Once you are confident you’ve found the correct partition, copy the UUID. Copying from the terminal emulator is typically done with ctrl+shift+C.

3. Adding an Entry to /etc/fstab

Now that we’ve obtained the UUID of our partition, it’s time to open up the fstab file.

Feel free to use your text editor of choice, in this example we will use nano. In order to edit the fstab file it must be opened as root:

Terminal window
❯ sudo nano /etc/fstab

Using the arrow keys, navigate to the bottom of the fstab file, and then on a new line we’ll create our new entry:

Terminal window
UUID=08A24E90A24E81E4 /media/windows ntfs3 defaults,nofail 0 0

The break down of this entry is as follows:

  • UUID=08A24E90A24E81E4 This is the file system we want to mount, identified by its UUID. There are other methods to identify your filesystem, though UUID tends to be safest. Additional methods listed here.

  • /media/windows The Linux Filesystem Hierarchy Standard says that /media/ is the proper location for removable drives to be mounted. windows indicates the directory we wish to mount our drive to. Each drive we want to mount will need its own directory.

  • ntfs3 This is the filesystem type for our file system. We are explicitly using the ntfs3 kernel driver in our example. Other examples would be ext4, xfs or similar. This explicit filesystem type declaration can be replaced with auto to allow the mount command to make its best guess.

  • defaults,nofail The options we want to pass to the mount command for this drive. nofail meaning that should this drive fail to mount, it will not cause an error while booting. Booting will continue like normal. defaults implies a standard set of logical options. Typically rw, ro, or similar.

  • the first 0 dump, this is typically deprecated in modern systems. Leaving this at 0 won’t hurt anything. Feel free to read more about it here.

  • the second 0 This sets the order for file system checks at boot time. For a root partition (unless your root file system is btrfs or xfs, which should be set to 0) this should be 1. All other file systems in your fstab should be either 0 (disabled) or 2. More information here.

Options are explained here and here in much more detail.

More info

As an aside, all options after the filesystem type declaration are optional if you do not change them from the default.

Thus

UUID=<partition UUID> /media/foo somefs

and

UUID=<partition UUID> /media/foo somefs defaults 0 0

are equivalent. somefs followed by nothing is implicitly somefs defaults 0 0

Important for Windows Partitions

If you are following this guide with a Windows partition your options should be uid=1000,gid=1000,rw,user,exec,umask=000 replacing uid and gid with your user id and group id. If you do not give user, and exec permissions, Windows may lock your drive leaving you unable to modify anything. This may happen regardless of permissions if you do not disable fast boot.

If you do not set umask=000 some files may be unwritable depending

4. Finishing Up

If you wish to mount the drive you created an entry for now, you need to run the following:

Terminal window
❯ sudo systemctl daemon-reload

and then:

Terminal window
❯ sudo mount -a

Your drive should now appear under /media/windows, and will appear there the next time you boot, as well as moving forward.

Terminal window
❯ ls /media/windows
'$Recycle.Bin'             Linux                  SteamLibrary
 AMD                       Modding                swapfile.sys
 Apps                      pagefile.sys          'System Volume Information'
 bootTel.dat               PerfLogs               Users
 Development               ProgramData            WiiU
'Documents and Settings'  'Program Files'         Windows
 DumpStack.log.tmp        'Program Files (x86)'   XboxGames
 FanControl                Recovery               xiv_modding
 Games                     RetroArch-Win64
 Intel                    'Ship of Harkinian'

If you wish to create a link to your newly mounted drive in your home directory you can run the following

Terminal window
❯ ln -s /media/windows ~/Windows`

To show it worked

Terminal window
❯ ls ~/Windows
'$Recycle.Bin'             Linux                  SteamLibrary
AMD                       Modding                swapfile.sys
Apps                      pagefile.sys          'System Volume Information'
bootTel.dat               PerfLogs               Users
Development               ProgramData            WiiU
'Documents and Settings'  'Program Files'         Windows
DumpStack.log.tmp        'Program Files (x86)'   XboxGames
FanControl                Recovery               xiv_modding
Games                     RetroArch-Win64
Intel                    'Ship of Harkinian'

tl;dr

  • Find the UUID of your partition
Terminal window
lsblk -f
  • Open /etc/fstab
Terminal window
sudo nano /etc/fstab
  • Create an entry in the bottom of the file
Terminal window
UUID=<partition UUID> /media/foo somefs defaults 0 0

Replacing <partition UUID>, foo, and somefs with your UUID, directory, and filesystem. eg., ext4, as well as setting any other options you may want after defaults, such as _netdev for a NAS, or nofail for any non-critical drive.

  • Reload your daemon
Terminal window
❯ sudo systemctl daemon-reload
  • Mount your drive
Terminal window
❯ sudo mount -a

This drive is now mounted, and will now be mounted on boot moving forward as well.

Additional reading