Ubuntu 14.04 - need help on umount

I am using Ubuntu 14.04. I am trying to create a bootable memory card for my tinkerboard. When i do

lsblk

I get the following output:

NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 465.8G  0 disk 
├─sda1   8:1    0 458.1G  0 part /
├─sda2   8:2    0     1K  0 part 
└─sda5   8:5    0   7.7G  0 part [SWAP]
sdb      8:16   1  14.9G  0 disk 
├─sdb1   8:17   1    64M  0 part /media/mycomp/7458-EBF2
└─sdb2   8:18   1  14.8G  0 part /media/mycomp/7496-D5D4
sr0     11:0    1  1024M  0 rom

In this sdb is what I have to unmount. I issued the following command:

sudo umount /sdb
sudo umount /sdb/sdb*
sudo umount /sdb/sdb1
sudo umount /sdb/sdb2

None of them works. How can I unmount the memory card so that I can write img file into the memory card.

mount command shows these options though: among various options:-

/dev/sdb1 on /media/mycomp/7458-EBF2 type vfat (rw,nosuid,nodev,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec,flush,uhelper=udisks2)
/dev/sdb2 on /media/mycomp/7496-D5D4 type vfat (rw,nosuid,nodev,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec,flush,uhelper=udisks2)

However, when I try

sudo umount /dev/sdb1
sudo umount /dev/sdb2
sudo umount /dev/sdb*

I get the similar error

/dev/sdb1 not mounted

Apricot

Posted 2017-09-01T13:51:25.990

Reputation: 101

An example error message umount: /sdb: not found : common for all the options – Apricot – 2017-09-01T13:56:48.507

How about /dev/sdb1? :) What is the output of mount in the first place? – Kamil Maciorowski – 2017-09-01T13:58:49.797

i did that too...getting similar error...have updated my question – Apricot – 2017-09-01T14:00:55.070

Try sudo umount /media/mycomp/7458-EBF2 – gronostaj – 2017-09-01T14:08:51.427

Ubuntu 14.04 - need help on umount

No answers