How to manually mount a USB flash drive in a non-graphical environment

Environment

• Red Hat Enterprise Linux 4
• Red Hat Enterprise Linux 5
• Red Hat Enterprise Linux 6
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8
• Red Hat Enterprise Linux 9

Issue

• How do I mount a USB flash drive from the command line?
• How do I disconnect the USB flash drive?

Resolution

1. Monitor the system messages log to see what device the USB key is assigned to.

• For RHEL 7 and earlier, run tail -f /var/log/messages as root.
• For RHEL 8 and later, run journalctl -f as root.
• lsblk command can be used to list all detected block devices.

2. Once a device node has been assigned to the key (sdXy where X is a letter and y is a partition number), press 'CTRL + C' to exit the tail.

3. Create a directory to mount the device in:

    # mkdir -p /mnt/usb
   

4. Mount the appropriate partition from the USB drive into that new directory:

    # mount /dev/sdXy /mnt/usb
   

5. Use the USB drive via /mnt/usb/

6. Unmount the filesystem.

    # umount /mnt/usb
   

7. Check if the filesystem has been unmountd.

    # lsblk
    or
    # cat /proc/mounts | grep /mnt/sdXy
   

8. Disconnect the USB drive.

Diagnostic Steps

• Review the system logs at /var/log/messages or in journalctl to determine which device the USB drive was added as. The following example presents sdb1:

# tail -n 18 -f /var/log/messages
Aug  2 11:01:32 host1 kernel: usb 1-8: new high speed USB device number 6 using ehci_hcd  <----- New USB device 
Aug  2 11:01:32 host1 kernel: usb 1-8: New USB device found, idVendor=0781, idProduct=5530
Aug  2 11:01:32 host1 kernel: usb 1-8: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Aug  2 11:01:32 host1 kernel: usb 1-8: Product: Cruzer
Aug  2 11:01:32 host1 kernel: usb 1-8: Manufacturer: SanDisk
Aug  2 11:01:32 host1 kernel: usb 1-8: SerialNumber: x
Aug  2 11:01:32 host1 kernel: usb 1-8: configuration #1 chosen from 1 choice
Aug  2 11:01:32 host1 kernel: scsi11 : SCSI emulation for USB Mass Storage devices
Aug  2 11:01:33 host1 kernel: scsi 11:0:0:0: Direct-Access     SanDisk  Cruzer           1.26 PQ: 0 ANSI: 5
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: Attached scsi generic sg2 type 0
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: [sdb] 62530624 512-byte logical blocks: (32.0 GB/29.8 GiB)   <--- sdb
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: [sdb] Write Protect is off
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: [sdb] Assuming drive cache: write through
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: [sdb] Assuming drive cache: write through
Aug  2 11:01:33 host1 kernel: sdb: sdb1                                        <---------- partition on sdb1 
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: [sdb] Assuming drive cache: write through
Aug  2 11:01:33 host1 kernel: sd 11:0:0:0: [sdb] Attached SCSI removable disk

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