[SOLVED] Empty /boot but arch works fine

matcharles · 2015-03-18 23:50:32

Hello all,

I have just recently moved from debian to arch on my main computer. So far I love the distro and I find having bleeding edge software to be AWESOME in contrast to debian's release cycle but I digress.

I followed the beginner's guide to the T and installed arch on my first try. However good this is working, my /boot shows empty once I am logged into my computer and I know better than suppose this is normal behavior. Here are the info I think you will want to look at, let me know if there is anything missing (still a beginner!).

/etc/fstab (Mounted sda1 (EFI) and sda2 (ext4 /boot) to /boot. This is a part I am not fully comfortable with as I don't understand why I need to mount 2 partitions into /boot... like how does that even work?)

└─> cat /etc/fstab
# 
# /etc/fstab: static file system information
#
# <file system>	<dir>	<type>	<options>	<dump>	<pass>
# /dev/sda3 LABEL=root
UUID=e78bd164-412a-49c2-a8d7-a02be83764ac	/         	ext4      	rw,relatime,data=ordered,discard	0 1

# /dev/sda2 LABEL=boot
UUID=509fa6cb-9c3f-40b9-a307-942646a6649b	/boot     	ext4      	rw,relatime,data=ordered	0 2

# /dev/sda1 LABEL=efi
UUID=2B0D-A043      	/boot     	vfat      	rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro	0 2

# /dev/sdb1 LABEL=home
UUID=7eb041f8-6550-40de-bbda-c6fbfb682b55	/home     	ext4      	rw,relatime,data=ordered	0 2

# /dev/sdb2 LABEL=var
UUID=ea1d196a-f2fe-4eec-936e-68ca0131dcff	/var      	ext4      	rw,relatime,data=ordered	0 2

# /dev/sdb3
UUID=b0027b90-2f05-4b86-b5b5-a7751af3329e	none      	swap      	defaults  	0 0

lsblk

└─> lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 111.8G  0 disk 
├─sda1   8:1    0   513M  0 part 
├─sda2   8:2    0  1000M  0 part /boot
└─sda3   8:3    0  90.8G  0 part /
sdb      8:16   0   2.7T  0 disk 
├─sdb1   8:17   0   2.7T  0 part /home
├─sdb2   8:18   0    10G  0 part /var
└─sdb3   8:19   0     8G  0 part [SWAP]
sr0     11:0    1  1024M  0 rom

parted /dev/sda print

Model: ATA KINGSTON SV300S3 (scsi)
Disk /dev/sda: 120GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name  Flags
 1      1049kB  539MB   538MB   fat32              boot, esp
 2      539MB   1588MB  1049MB  ext4
 3      1588MB  99.1GB  97.5GB  ext4

So, before I try anything stupid (as in commenting out sda2 from my fstab), I wanted to have your opinion on what's going on here.

I did read these two threads, but not sure how they apply to my situation:
https://bbs.archlinux.org/viewtopic.php?id=184392
https://bbs.archlinux.org/viewtopic.php?id=145444

Thanks for your time!

Last edited by matcharles (2015-03-20 10:17:56)

Knute · 2015-03-18 23:54:56

The reason that your /boot partition is empty is because your system is set up to unmount the boot partition after it's done with it. It's a security thing, I guess.
If you want to see what's in there simply mount /boot and then you should be able to look in it.

HTH

teateawhy · 2015-03-19 01:00:56

It's perfectly fine to have a running linux system where /boot is empty. The files in /boot are only needed by the bootloader.
That said you want to make sure that pacman places the kernel file on the /boot partition when the kernel is updated and not on the / partition, therefore you need to have /boot mounted before updating the linux package.

Now to the fact that you have two different partitions for /boot. I don't think you have followed the beginner's guide correctly, because it does NOT instruct you to create a seperate boot partition, it tells you to create an ESP and mount the ESP to /boot.

I can't say for sure why your /boot is empty. I guess that during installation you mounted /dev/sda1 to /boot, and later fstab mounts /dev/sda2 to /boot because it is first, and the fstab entry for /dev/sda1 is ignored because it comes second. In that case the solution would be to uncomment sda2, as you suggested, and do whatever you want with the useless sda2 partition.

To check, try this

# umount /boot
# mount /dev/sda1 /boot
# ls /boot

matcharles · 2015-03-19 21:38:28

teateawhy wrote:

It's perfectly fine to have a running linux system where /boot is empty. The files in /boot are only needed by the bootloader.
That said you want to make sure that pacman places the kernel file on the /boot partition when the kernel is updated and not on the / partition, therefore you need to have /boot mounted before updating the linux package.
Now to the fact that you have two different partitions for /boot. I don't think you have followed the beginner's guide correctly, because it does NOT instruct you to create a seperate boot partition, it tells you to create an ESP and mount the ESP to /boot.
I can't say for sure why your /boot is empty. I guess that during installation you mounted /dev/sda1 to /boot, and later fstab mounts /dev/sda2 to /boot because it is first, and the fstab entry for /dev/sda1 is ignored because it comes second. In that case the solution would be to uncomment sda2, as you suggested, and do whatever you want with the useless sda2 partition.
To check, try this
# umount /boot
# mount /dev/sda1 /boot
# ls /boot

Thanks very much! I did get mixed up a bit regarding the whole EFI partition and /boot. So if I am getting this correctly, I should only have sda1 as EFI and mounted on /boot and no sda2 partition at all... correct? If that turns out to be correct, it would relieve me a bit of a headache trying to understand why mount 2 separate partitions on the same mount point.

Knute wrote:

The reason that your /boot partition is empty is because your system is set up to unmount the boot partition after it's done with it. It's a security thing, I guess.
If you want to see what's in there simply mount /boot and then you should be able to look in it.
HTH

That's actually a pretty good thing when you think about it.

matcharles · 2015-03-20 10:16:45

Can confirm removing /dev/sda2 from the fstab makes the system mount my ESP into /boot without issue. Marked as solved, even though the problem was behind the keyboard... You learn something new everyday hopefully! Thanks guys.

Arch Linux

#1 2015-03-18 23:50:32

[SOLVED] Empty /boot but arch works fine

#2 2015-03-18 23:54:56

Re: [SOLVED] Empty /boot but arch works fine

#3 2015-03-19 01:00:56

Re: [SOLVED] Empty /boot but arch works fine

#4 2015-03-19 21:38:28

Re: [SOLVED] Empty /boot but arch works fine

#5 2015-03-20 10:16:45

Re: [SOLVED] Empty /boot but arch works fine

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