partition appears to be mounted, but not according to umount or lsblk

[thyme after thyme]

Hello lovely debianizers,

My Debian 10 machine has two physical disks, sda and sdb. The
(encrypted) root filesystem is on sdb, meanwhile I’ve used
fstab/crypttab to mount an (encrypted) partition on sda to
/mnt/data01-hdd, where I’ve stored some stuff:

user@hostname:/$ ls -gh /mnt/data01-hdd/
total 4.0K
drwxr-xr-x 5 1007 4.0K Jan 1 23:02 backups

However, when i do
user@hostname:/$ sudo umount /mnt/data01-hdd

umount complains thus:
umount: /mnt/data01-hdd: not mounted.

How can I unmount the partition?

lsblk -f doesn’t show the partition as mounted, which is something that
I don’t understand:

user@hostname:~$ sudo lsblk -f
NAME FSTYPE LABEL UUID
FSAVAIL FSUSE% MOUNTPOINT

sda
└─sda1 crypto_LUKS
400a161c-0654-4596-9b1c-3900ef504cb5
└─sda1_crypt LVM2_member
6I1ePw-7IuN-DQqN-02rs-vDgM-e3Nh-DUkfK0
└─1Terabyte01--vg-data01 ext4
900e8322-5af6-4ecd-827d-fae54f21e4f3
sdb
├─sdb1 ext2
0791c90e-8567-48c9-90a8-67c7c6619359 359.1M 18% /boot

├─sdb2
└─sdb5 crypto_LUKS
2b5a5240-9d34-42af-958a-a2a4509382d8
└─sdb5_crypt LVM2_member
q9xOdL-yo0s-CDK9-eYiV-0uya-sX7o-WIvPZH
├─debian--vg-root ext4
4248fdef-e86c-456a-8fc7-2a4ec5b1b0df 195.7G 52% /

└─debian--vg-swap_1 swap
5cc35d37-c746-4bc5-9d00-f437061f6cc8 [SWAP]

The configuration files:

user@hostname:/$ cat /etc/fstab
# /etc/fstab: static file system information.
# <file system> <mount point> <type>
<options> <dump> <pass>
/dev/mapper/debian--vg-root / ext4
errors=remount-ro 0 1
# /boot was on /dev/sdb1 during installation
UUID=0791c90e-8567-48c9-90a8-67c7c6619359 /boot ext2
defaults 0 2
/dev/mapper/debian--vg-swap_1 none swap sw
0 0

# 1000gb hdd via its LVM, cf. also /etc/crypttab
#/dev/mapper/1Terabyte01--vg-data01 /mnt/data01-hdd ext4
default


user@hostname:/$ cat /etc/crypttab
# sdb5 - debian 10 / yunohost on 500Gb HDD
# Tell cryptsetup to create the volume sdb5_crypt from /dev/sdb5
(identified
# by its UUID). Don't use a key file. Since this is the root device, it
will
# automatically be processed during the initramfs stage of boot (making
it
# accessible to dropbear).
#
sdb5_crypt UUID=2b5a5240-9d34-42af-958a-a2a4509382d8 none luks,discard

# sda1 - data on 1000Gb HDD
# Tell cryptsetup to create the volume sda1_crypt from /dev/sda1
(identified
# by its UUID) using the sda1.luks key. Since this is not a root device,
we
# explicitly require that the device be processed during the initramfs
stage.
#
sda1_crypt UUID=400a161c-0654-4596-9b1c-3900ef504cb5 /etc/keys/sda1.luks
luks,initramfs

I’d much apreciate your guidance!

Thyme Harp

[Charles Curley]

On Thu, 19 Jan 2023 23:03:14 +0000
thyme after thyme <thyme...@riseup.net> wrote:

> However, when i do
> user@hostname:/$ sudo umount /mnt/data01-hdd
>
> umount complains thus:
> umount: /mnt/data01-hdd: not mounted.

First off, don't tell us what the program did, show us exactly what the
program did by copying and pasting the initial prompt, the command, and
the following prompt. Like so:

root@ideapc:~# umount /media/disk
umount: /media/disk: not mounted.
root@ideapc:~#

>
> How can I unmount the partition?

I haven't seen any evidence that the partition has ever been mounted.
When and how do you think it was mounted, and how do you know? Have you
tried mounting it manually?

Your fstab has the following two (unwrapped) lines:

# 1000gb hdd via its LVM, cf. also /etc/crypttab
#/dev/mapper/1Terabyte01--vg-data01 /mnt/data01-hdd ext4 default

That sharp (#) at the beginning of the second line means that line is
commented out. So I suspect the volume never was mounted.


--
Does anybody read signatures any more?

https://charlescurley.com
https://charlescurley.com/blog/

[to...@tuxteam.de]

On Thu, Jan 19, 2023 at 11:03:14PM +0000, thyme after thyme wrote:
> Hello lovely debianizers,
>
> My Debian 10 machine has two physical disks, sda and sdb. The
> (encrypted) root filesystem is on sdb, meanwhile I’ve used
> fstab/crypttab to mount an (encrypted) partition on sda to
> /mnt/data01-hdd, where I’ve stored some stuff:
>
> user@hostname:/$ ls -gh /mnt/data01-hdd/
> total 4.0K
> drwxr-xr-x 5 1007 4.0K Jan 1 23:02 backups

Perhaps that stuff is just on the directory (using space
in the partition containing that directory...

> However, when i do
> user@hostname:/$ sudo umount /mnt/data01-hdd
>
> umount complains thus:
> umount: /mnt/data01-hdd: not mounted.

...and the partition you think is mounted isn't, after all?

You mount stuff on directories. Those are just plain old directories
and you can put stuff in them without having anything mounted.

Cheers
--
t

[Jude DaShiell]

I wonder if blkid might be a bit more informative.



Jude <jdashiel at panix dot com>
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)

.

On Fri, 20 Jan 2023, to...@tuxteam.de wrote:

> On Thu, Jan 19, 2023 at 11:03:14PM +0000, thyme after thyme wrote:
> > Hello lovely debianizers,
> >
> > My Debian 10 machine has two physical disks, sda and sdb. The

> > (encrypted) root filesystem is on sdb, meanwhile I?ve used

> > fstab/crypttab to mount an (encrypted) partition on sda to

> > /mnt/data01-hdd, where I?ve stored some stuff:

[thyme after thyme]

Charles and tomas, you were both right in your guesses. Thanks a billion
for the help!

[Anssi Saari]

Jude DaShiell <jdas...@panix.com> writes:

> I wonder if blkid might be a bit more informative.

I don't know, I usually run mount without arguments to see what's
mounted or look in the file /proc/mounts.

[Cindy Sue Causey]

A super simple grep, e.g. "mount|grep sdc", works on it, too. I do it
all the time because it filters out the (visual) noise.

Every since I realized that, my chroot dismounts never fail. Prior to
that, I was having to mostly reboot to dislodge a chroot that had some
or another too "busy" to umount mount point that I couldn't ferret
out.

Cindy :)
--
Talking Rock, Pickens County, Georgia, USA
* runs with birdseed *

[to...@tuxteam.de]

On Fri, Jan 20, 2023 at 09:19:16AM +0000, thyme after thyme wrote:
>
> Charles and tomas, you were both right in your guesses. Thanks a billion
> for the help!

Glad you found it :)

Cheers
--
t