The following tutorial explains how to mount USB drive in CentOS system using terminal and shell command line. If you are using desktop manager, you will most likely be able to use it to mount USB drive for you.
Mounting USB drive is no different than mounting USB stick or even a regular SATA drive. The video example below will illustrate the entire process of mounting USB drive on CentOS system. To gain more understating read the subsequent paragraphs.
Detecting USB hard drive
After you plug in your USB device to your USB port, Linux system adds a new block device into
/dev/ directory. At this stage, you are not able to use this device as the USB filesystem needs to be mouted before you can retrieve or store any data. To find out what name your block device file have you can run
fdisk -l command.
fdisk command required administrative privileges to access the required information, thus from this reason the commands needs to be executed as a root user or with
# fdisk -l OR $ sudo fdisk -l
Upon executing the above command you will get an output similar to the one below:
Disk /dev/sdc: 7.4 GiB, 7948206080 bytes, 15523840 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x00000000 Device Boot Start End Sectors Size Id Type /dev/sdc1 * 8192 15523839 15515648 7.4G b W95 FAT32
The above output will most likely list multiple disks attached to your system. Look for your USB drive based on its size and filesystem. Once ready, take a note of the block device name of the partition you intent to mount. For example in our case that will be
/dev/sdc1 with FAT32 filesystem.
Create mount point
Before we are able to use
mount command to mount the USB partition, we need to create a mount point. Mount point can be any new or existing directory within your host filesystem. Use
mkdir command to create a new mount point directory where you want to mount your USB device:
# mkdir /media/usb-drive
Mount USB Drive
At this stage we are ready to mount our USB’s partition
/media/usb-drive mount point:
# mount /dev/sdc1 /media/usb-drive/
To check whether your USB drive has been mounted correctly execute
mount command again without any arguments and use
grep to search for USB block device name:
# mount | grep sdc1 /dev/sdc1 on /media/usb-drive type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro
If no output has been produced by the above
mount command your USB partition is not mounted. Alternatively, double-check whether you have used a correct block device name in the above command.
Accessing USB Data
If all went well, we can access our USB data simply by navigating to our previously created mount point
# cd /media/usb-drive
Before we are able to unmount our USB partition we need to make sure that no process is using or accessing our mount point directory, otherwise we will receive an error message similar to the one below:
umount: /media/usb-drive: target is busy (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1).)
Close your shell or navigate away from USB mount point and execute the following command to unmount your USB drive:
# umount /media/usb-drive
In order to mount USB drive permanently after reboot add the following line into your
/etc/fstab config file:
/dev/sdc1 /media/usb-drive vfat defaults 0 0
However, the above mount line may fail if you add or remove additional drives from your Linux system. From this reason it is recommend to use partition
UUID instead of a raw block device name. To do so, first locate a UUID of your USB drive:
# ls -l /dev/disk/by-uuid/* lrwxrwxrwx 1 root root 10 Mar 27 23:38 /dev/disk/by-uuid/2016-08-30-11-31-31-00 -> ../../sdb1 lrwxrwxrwx 1 root root 10 Mar 27 23:38 /dev/disk/by-uuid/3eccfd4e-bd8b-4b5f-9fd8-4414a32ac289 -> ../../sda1 lrwxrwxrwx 1 root root 10 Mar 27 23:38 /dev/disk/by-uuid/4082248b-809d-4e63-93d2-56b5f13c875f -> ../../sda5 lrwxrwxrwx 1 root root 10 Mar 28 01:09 /dev/disk/by-uuid/8765-4321 -> ../../sdc1 lrwxrwxrwx 1 root root 10 Mar 27 23:38 /dev/disk/by-uuid/E6E3-F2A2 -> ../../sdb2
Based on the above
ls command output we can see that the UUID belonging to block device
8765-4321 thus our
/etc/fstab mount line will be:
/dev/disk/by-uuid/8765-4321 /media/usb-drive vfat 0 0
mount -a command to mount all not yet mounted devices.
# mount -a