LPIC 101 exam
104.3 Control mounting and unmounting of filesystems (3)
Configure the mounting of a filesystem. Tasks include manually mounting and unmounting filesystems, configuring filesystem mounting on bootup, and configuring user-mountable removable filesystems.
Mount and unmount filesystems manually Configure filesystem mounting on bootup Configure user-mountable, removable filesystems Mounting and Unmounting
Describe the linux filesystem concept. A huge tree. There are other kinds of mountings: tmpfs, NFS, ..
It is better to mount on empty directories
cat /et/fstab basic mount command mount a drive unmount a drive
mount -t ext4 /dev/sda1 /media mount -o remount,ro /dev/sda1
Get info on UUID and Label and Format
file system: Label, UUID, device mount point: swap or none for swap type: can be auto options: defaults, rw / ro, noauto, user, exec / noexec, noatime dump: do dump command backup this? mostly 0 pass: Non-zero values of pass specify the order of checking filesystems at boot time (seen in Integrity of file ystems) note: - User-mounted filesystems default to noexec unless exec is specified afteruser. - noatime will disable recording of access times. Not using access times may improve performance.
swapon swapoff swapon -s
Create and change hard & symbolic links (2)
Key Knowledge Areas
Create links. Identify hard and/or softlinks. Copying versus linking files. Use links to support system administration tasks.
On a storage device, a file or directory is contained in a collection of blocks. Information about a file is contained in an inode, which records information such as the owner, when the file was last accessed, how large it is, whether it is a directory or not, and who can read from or write to it.
$ ls -i $ ls -R
A link is simply an additional directory entry for a file or directory
$ ls -il $ vi link2file.txt #will edit both $ mv myfile.txt
A link is simply an additional directory entry for a file or directory, allowing two or more names for the same thing. A hard link is a directory entry that points to an inode, while a soft link or symbolic link is a directory entry that points to an inode that provides the name of another directory entry. The exact mechanism for storing the second name may depend on both the file system and the length of the name. Symbolic links are also called symlinks.
Soft links, or symlinks, merely point to another file or directory by name rather than by inode. Soft links can cross file system boundaries.
$ cp myfile.txt newfile.txt $ vi myfile.txt $ cat myfile.txt $ cat softlink.txt $ cat hardlink.txt $ cat newfile.txt $ ls -il
You can create hard links only for files and not for directories. The exception is the special directory entries in a directory for the directory itself and for its parent (. and ..)
$ ls -ltrhi /etc/grub2.cfg
You will get an error if you attempt to create hard links that cross file systems or that are for directories.
$ ln mydir link2dir # error! $ ln -s mydir link2dir
If you are using relative names, you will usually want the current working directory to be the directory where you are creating the link; otherwise, the link you create will be relative to another point in the file system.
$ ln -s myfile.txt mydir/ #broken link
$ cd mydir $ ln -s ../myfile.txt .
we can find symbloic links with ls -i or even find:
$ find . -type l
and they are useful!
$ which java # linking to specific versions $ ls -ltrhi /etc/grub2.cfg # easier admin tasks $ ls -l /usr/lib64/ # keeping libraries clean