Load the ext4 module so that CentOS5.x supports the ext4 file system

Recently, we have to perform a test to restore a file by mistake using the rm command in the ext4 file system. we need to format a hard disk into the ext4 file system. The result is: [root @ server ~] # Mkfs. ext4/dev/sdb1-bash: mkfs. ext4: commandnotfound I didn't load the ext4 module on the system before.

Recently, we have to perform a test to restore a file by mistake using the rm command in the ext4 file system. we need to format a hard disk into the ext4 file system, and the result returns an error:

[Root @ server ~] # Mkfs. ext4/dev/sdb1 -Bash: mkfs. ext4: command not found

I didn't load the ext4 module on the system before, and I was prompted that I didn't have this command, so I would like to configure it first (kernel version: 2.6.18-194. el5 ).

PS: CentOS 5.x contains the ext4 module, but it is not loaded. you need to manually add the module to the system.

[Root @ server ~] # Cd/lib/modules/2.6.18-194. el5/kernel/fs/ext4/ [Root @ server ext4] # ll Total 288 -Rwxr -- r -- 1 root 285684 2010-04-03 ext4.ko

After finding the module, run the modprobe command to add it:

[Root @ server ext4] # modprobe ext4 // Note: Only the module name can be written, but not ext4.ko.

After the ext4 module is added, use lsmod to view it:

[Root @ server ext4] # lsmod | grep ext4 Ext4 243693 0 Jbd2 58329 1 ext4 Crc16 6209 1 ext4

Install the e4fsprogs software (otherwise, the error-bash: mkfs. ext4: command not found will still occur)

[Root @ server ext4] # yum-y install e4fsprogs

Format the hard disk again:

[Root @ server ext4] # cd ~ [Root @ server ~] # Mkfs. ext4/dev/sdb1 Mke4fs 1.41.12 (17-May-2010) Filesystem label = OS type: Linux Block size = 4096 (log = 2) Fragment size = 4096 (log = 2) Stride = 0 blocks, Stripe width = 0 blocks 655360 inodes, 2620595 blocks 131029 blocks (5.00%) reserved for the super user First data block = 0 Maximum filesystem blocks = 2684354560 80 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768,983 04, 163840,229 376, 294912,819 200, 884736,160 5632 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 24 mounts or 180 days, whichever comes first. Use tune4fs-c or-I to override.

The system prompts that the formatting is successful. Attach a new disk and view the file system format:

[Root @ server ~] # Mkdir/mnt/test [Root @ server ~] # Mount/dev/sdb1/mnt/test/ [Root @ server ~] # Df-Th File system type capacity available in use % mount point /Dev/sda2 ext3 20G 2.9G 16G 17%/ /Dev/sda1 ext3 122 M 12 M 104 M 10%/boot Tmpfs 95 M 0 95 M 0%/dev/shm /Dev/sdb1 ext4 9.9G 151 M 9.2G 2%/mnt/test

Finally, configure to automatically mount the new disk (sdb1) at startup ):

[Root @ server ~] # Vi/etc/fstab LABEL = // ext3 defaults 1 1 LABEL =/boot ext3 defaults 1 2 Tmpfs/dev/shm tmpfs defaults 0 0 Devpts/dev/pts devpts gid = 5, mode = 620 0 0 Sysfs/sys sysfs defaults 0 0 Proc/proc defaults 0 0 LABEL = SWAP-sda3 swap defaults 0 0 /Dev/sdb1/mnt/test ext4 defaults 0 0