Formatting Linux filesystem is an essential task for sysadmin and may required for many reasons such as installing a new disk on server. If you want to expand file system or you just add a new hard disk drive or create separate partitions for security and performance reasons. Whatever may be your reason(s) all file system creating involves creations of superblock, inode and other filesystem metadata structure. Fortunately, Linux comes with mkfs command to format filesystem. It is used to build a Linux file system on a device, usually a hard disk partition. General syntax of mkfs is as follows:
mkfs -t filetype /dev/DEVICE
- -t filetype : File system type, it can be ext3, ext2, etc4, vfat etc
- /dev/DEVICE : Your device name i.e. partition /dev/hda1 or /dev/sda1 etc.
Suppose you would like to format /dev/hda5 with ext3 file system.
Warning: The first task is to allocate disk space for Linux. You will need to set up a partitioning scheme for your hard disk using a program called fdisk command.
Step #1 Create the new filesystem with following command (first login in as a root user)
# mkfs.ext3 /dev/sda5
mke2fs 1.35 (28-Feb-2004) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) 30120 inodes, 120456 blocks 6022 blocks (5.00%) reserved for the super user First data block=1 15 block groups 8192 blocks per group, 8192 fragments per group 2008 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729 Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 38 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.
Step # 2: Create mount point directory for the file system
# mkdir /datadisk1
Step # 3: Mount the new file system
# mount /dev/sda5 /datadisk1
Step # 4: Finally make sure file system /dev/hda5 automatically mounted at /datadisk1 mount point after system reboots. You need to add partition to /etc/fstab file. Use text editor such as vi to add following entry
# vi /etc/fstab
Add/append following entry to file:
/dev/sda5 /datadisk1 ext3 defaults 0 2
- /dev/sda5 : File system or parition name
- /datadisk1 : Mount point
- ext3 : File system type
- defaults : Mount options (Read man page of mount command for all options)
- 0 : Indicates whether you need to include or exclude this filesystem from dump command backup. Zero means this filesystem does not required dump.
- 2 : It is used by the fsck program to determine the order in which filesystem checks are done at reboot time. The root (/) filesystem should be specified with a #1, and otherfilesystems should have a # 2 value.
Save file and exit to shell prompt. For more information see mkfs(8) page.