Help with mounting a drive

anon78342405 · September 10, 2021, 7:17am

To put it simply, last night I installed and set up Timeshift to do weekly snapshots to my newly appointed and repartitioned Backup Drive. I added the drive to fstab. I then did not reboot, left my system as is and went to sleep.

In the morning, I did my daily updates in the Terminal, which included a Kernel update. From 5.13.13 to 5.14.2. I rebooted and was greeted with emergency mode, and an error saying one of my drives has timed out.

Now, I thought this was my boot drive, but after a bit of ducking I found out that you can’t really get into emergency mode if your boot drive wasn’t detected and mounted.

I checked the UUID and compared it against the UUIDs of my drives in fstab. I noticed that my backup drive’s UUID & path did not match up after the partitioning, so I fixed that. Didn’t help.

Then I straight up mounted my boot drive in a live EndeavourOS USB and tried reinstalling the kernel, did not help.

What helped was removing the Backup Drive from my /etc/fstab. I suppose the bootloader somehow detected the backed up files on my drive as a file system and tried to boot off of that? That’s what I’m getting out of this and was wondering if I am correct in this regard.

The Backup Drive can be manually mounted by clicking on it in Dolphin, no problem.

What I thought was my first “arch moment” of instability was actually an user error. Oops c:

otherbarry · September 10, 2021, 7:23am

Did you use the nofail mounting option in fstab?

Kresimir · September 10, 2021, 7:24am

You probably made a mistake with your /etc/fstab entry.

If you want to try again and want some help, please provide the output of:

lsblk -o name,uuid,fstype,size

Is the drive external or internal?

anon78342405 · September 10, 2021, 7:27am

I am fine with mounting it manually, but here:

[emilie@arch ~]$ lsblk -o name,uuid,fstype,size
NAME        UUID                                 FSTYPE   SIZE
sda                                                     931.5G
└─sda1      d61b73e6-62a7-4c53-9e7a-3255c1a58731 ext4   931.5G
sdb                                                     476.9G
└─sdb1      78dade95-656d-4413-a1b3-042498a38dab ext4   476.9G
sdc                                                     931.5G
└─sdc1      2a533e5b-8efc-4767-8d7a-044f236fffe2 ext4   931.5G
nvme0n1                                                 465.8G
├─nvme0n1p1 2BCC-0124                            vfat       1G
├─nvme0n1p2 5f002bf8-0d6d-414e-852d-37d948b923c9 swap      16G
└─nvme0n1p3 ace3457e-3837-445f-8fb7-5868f0278ecf ext4   448.8G
[emilie@arch ~]$

My backup drive would be the 476 GB one. And nope, I did not add nofail as an option.
Drive is internal.

Kresimir · September 10, 2021, 7:27am

Then you do not need nofail. Which drive is it? sdc1?

anon78342405 · September 10, 2021, 7:28am

sdb1.

otherbarry · September 10, 2021, 7:30am

cat /etc/fstab

Any relevant dmesg errors?

Kresimir · September 10, 2021, 7:30am

This should work, just add it to your /etc/fstab. Do not change anything else, of course.

UUID=78dade95-656d-4413-a1b3-042498a38dab   /home/username/backup   ext4   defaults,noatime   0 2

Make sure the directory /home/username/backup exists (change it to whatever you want, but it must exist).

anon78342405 · September 10, 2021, 7:33am

Here:

[emilie@arch ~]$ 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>
UUID=2BCC-0124                            /boot/efi      vfat    umask=0077 0 2
UUID=ace3457e-3837-445f-8fb7-5868f0278ecf /              ext4    defaults,noatime 0 1
# Crucial MX500 1
UUID=d61b73e6-62a7-4c53-9e7a-3255c1a58731 /run/media/emilie/d61b73e6-62a7-4c53-9e7a-3255c1a58731 ext4 user,errors=remount-ro,auto,exec,rw
# Crucial MX500 2
UUID=2a533e5b-8efc-4767-8d7a-044f236fffe2 /run/media/emilie/2a533e5b-8efc-4767-8d7a-044f236fffe2 ext4 user,errors=remount-ro,auto,exec,rw
[emilie@arch ~]$

The entry for my backup drive was this:

# Backup Drive
UUID=78dade95-656d-4413-a1b3-042498a38dab /run/media/emilie/78dade95-656d-4413-a1b3-042498a38dab ext4 user,errors=remount-ro,auto,exec,rw

@Kresimir I will try the entry you suggested. Any issues or unnecessary arguments with my current fstab? I sorta just whipped it up after searching for a quick automount tutorial.

Kresimir · September 10, 2021, 7:39am

I wouldn’t do it that way.

/run/media/emilie/d61b73e6-62a7-4c53-9e7a-3255c1a58731

You can, but why? Why not just create a directory for it somewhere in your filesystem? Even in root like /backup_drive works.

Also,

user,errors=remount-ro,auto,exec,rw

I’d just set options to defaults,noatime 0 2 for any additional ext4 drive (not for root).

anon78342405 · September 10, 2021, 7:43am

Alright I’ll change the arguments. I hope this lets the drive be readable and writable since these are my Steam library drives.

By the way I might have found out why this whole thing happened. Timeshift changed the directory of the drive from my usual /run/media/emilie to… /run/timeshift/backup.

So here’s my final adjusted 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>
UUID=2BCC-0124                            /boot/efi      vfat    umask=0077 0 2
UUID=ace3457e-3837-445f-8fb7-5868f0278ecf /              ext4    defaults,noatime 0 1
# Crucial MX500 1
UUID=d61b73e6-62a7-4c53-9e7a-3255c1a58731 /run/media/emilie/CrucialMX500 ext4 defaults,noatime 0 2
# Crucial MX500 2
UUID=2a533e5b-8efc-4767-8d7a-044f236fffe2 /run/media/emilie/CrucialMX5001 ext4 defaults,noatime 0 2
# Backup Drive
UUID=78dade95-656d-4413-a1b3-042498a38dab /run/timeshift/backup/ ext4 defaults,noatime 0 2

Kresimir · September 10, 2021, 7:45am

You can’t mess this up. The worst that can happen is that your computer won’t boot

But that is easily fixed with a live ISO (just restore a backup fstab that works).

Just make sure those <mount point> directories exist.

Your drives should be safe, but you should have a backup of important files. Regardless of any of this.

keybreak · September 10, 2021, 7:46am

@Kresimir

Won’t last slash create any unwanted problems though?

anon78342405 · September 10, 2021, 7:47am

Fixed

Kresimir · September 10, 2021, 7:47am

I’m not sure… I don’t think it should make problems, but I would get rid of it.

keybreak · September 10, 2021, 7:48am

I’m not sure either, just know that sometimes it means little different things (like when using rsync)

And usually people doesn’t do last slash inside /etc/fstab

Kresimir · September 10, 2021, 7:50am

I haven’t really thought about it. It’s a directory, directory paths can end in /. It would be logical that you could even have something absurd like: /run/timeshift/backup/././././../backup/.

I should try it…

keybreak · September 10, 2021, 7:51am

FOR THE SCIENCE!!!

P.S. Kids, don’t try it at home!

anon78342405 · September 10, 2021, 7:52am

Okay, going to reboot now and see if everything works. Fingers crossed!

pebcak · September 10, 2021, 7:55am

I have made a habit of running

sudo mount -a

whenever I make any changes to /etc/fstab to make sure everything will be mounted correctly. If it won’t, I would know it and fix it before rebooting.