CentOSv8

  Filesystems in Linux | Ext2, Ext3, Ext4, XFS, ZFS Repair in Linux ======== FSCK stands for File System Consistency Check & most of the times, it runs at boot time but can also be started manually by super user, if need arises. It can be used with 3 modes of operation; 1- Check for errors & let the user decide what should be done with each error. 2- Check for errors & make repairs automatically. 3- Check for errors & display the error but does not perform any repairs. We can use the FSCK command manually with the following syntax: # fsck options drives The options that can be used with fsck command are, -p      Automatic repair (no questions) -n      Make no changes to the filesystem -y      Assume “yes” to all questions -c      Check for bad blocks and add them to the badblock list -f      Force checking even if filesystem is marked clean -v     Be verbose -b     superblock Use alternative superblock -B     blocksize Force blocksize when looking for su

  I/O scheduler permanently in linux

  duf command in linux  iew Disk Usage iew Disk U

https://spalinux.com/2015/06/centos-7-basic-configure-firewall-by-firewall-cmd

https://spalinux.com/2015/06/centos-7-using-nmtui-to-modify-network-configuration

https://spalinux.com/2015/06/centos-7-use-chrony-to-sync-time-with-ntp-server