Managing storage media

mount - Mount a file system

• The process of attaching a storage device to the file system tree is called mounting.
• Usage: mount <device> <mountPoint>
• A file named /etc/fstab (short for file system table) lists the devices that are to be mounted at boot time.
• View a list of mounted file systems: mount
• Use the -t flag to specify the file system type.
• Examples:
  • mount
  • mount /dev/sdb1 /mnt/myUSB
  • mount -t iso9660 /dev/sdc /mnt/cdrom

umount - Umount a file system

• The process of detaching the storage media from the file system tree is called unmounting.
• Usage: umount <device>
• Always remember to umount your devices because, unmounting a device entails writing all the remaining data to the device so that it can be safely removed.
• Example:
  • umount /dev/sdb1

Check all devices

• You can check all the devices by listing the /dev directory.

TIP

• Using the tail -f /var/log/messages technique is a great way to watch what the system is doing in near real-time.

fdisk - Manipulate disk partition table

• fdisk allows us to interact directly with disk-like devices at a very low level.
• Usage: fdisk [arguments] [device]
• To view all devices: sudo fdisk -l
• Unmount your device before working on it with fdisk.
• To see a list of the available partition types use l command after entering fdisk interactive mode.
• To change a partition's system id use t command in interactive mode.
• To write the changes use w command in interactive mode.
• Examples:
  • sudo fdisk /dev/sdb

mkfs - Create a file system

• mkfs is short for make file system, it can create file systems in a variety of formats.
• Usage: mkfs [arguments] [device]
• Use the -t flag to specify system type.
• Examples:
  • sudo mkfs -t ext4 /dev/sdb1
  • sudo mkfs -t vfat /dev/sdb1

fsck - Check and repair system

• It stands for "file system check" and is used to check the integrity of file systems and repair corrupt file systems.
• Usage: sudo fsck [arguments] [device]
• Example:
  • sudo fsck /dev/sdb1

dd - Convert and copy a file

• It copies blocks of data from one place to another. So it can be used to clone devices.
• Usage: dd if=<input_file> of=<output_file> [bs=<block_size> [count=<blocks>]]
• Example:
  • dd if=/dev/sdb1 of=/home/carlos/flashDrive.iso

genisoimage (mkisofs) - Create an ISO 9660 image file

• To create an ISO image file containing the contents of a directory, we use the genisoimage program.
• Usage: genisoimage -o <outputFile> -R -J <directory>
• Example:
  • genisoimage -o cd-rom.iso -R -J ~/cd-rom-files

wodim (cdrecord) - Write data to optical storage media

• Blank out a CD-RW device: wodim dev=/dev/cdrw blank=fast
• Write an image into it: wodim dev=/dev/cdrw image.iso

md5sum - Calculate an MD5 checksum

• Used to calculate the MD5 checksum of a file.
• Usage: md5sum <file>
• Examples: md5sum secretFile.txt

df - disk free

• It is used to check the total and available space.
• Usage: df [options]
• Use the -h flag to view the space in human readable format.
• Example:
  • df
  • df -h