Ubuntu/etc/fstab Parsing

Ubuntu/etc/fstab parse and open/etc/fstab, you can see the following content: Shell code www.2cto.com [root @ localhost ~] # Cat/etc/fstab #/etc/fstab: static file system information. # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID = as a more robust way to name devices # that works even if disks are added and removed. see fstab (5 ). # <file system> <mount point> <type> <options> <dump> <pass> #/was on/dev/sda1 during installation UUID = 886f96a1-025d-43b9-9467-6 1177884dff7/ext4 errors = remount-ro 0 1 #/boot was on/dev/sda5 during installation UUID = f9908cbd-e556-4950-9588-803d77010c6d/boot ext4 defaults 0 2 #/home was on/dev/sda7 installation UUID = logs/home ext4 defaults 0 2 #/usr/local was on/dev/sda8 during installation UUID = logs/usr/local ext4 defaults 0 2 # swap was on/d Ev/sda6 during installation UUID = 611bb47a-b187-4407-a711-9e73ae4e08a3 none swap sw 0 0 it is actually a table, including <file system>, <mount point>, <type>, <options>, <dump>, and <pass> columns. The following is a one-to-one explanation. 1. <file system>: The device name of the file system to be mounted. It can also be a remote file system. For a local device, you can write/dev/sda1,/dev/sda5, and so on. For a remote file system, enter 192.168.10.36:/home /. You can also use the volume label or UUID (Universally Unique Identify globally Unique identifier. The default/etc/fstab is represented by UUID, which is not described here. 2. <mount point>: mount point, that is, locate or create a directory, and then mount the file system <file system> to this directory, then you can access the file system to be mounted from this directory. For swap partitions, this field should be set to none, indicating no mount point. 3. <type>: specifies the type of the file system. The following file systems are currently supported by Linux: adfs, befs, cifs, ext3, ext2, ext, iso9660, kafs, minix, msdos, vfat, umsdos, proc, reiserfs, swap, squashfs, nfs, hpfs, ncpfs, ntfs, affs, ufs. 4. <options>: Enter the setting options here. Each option is separated by a comma. Because there are many options, and the space here is limited, we will not introduce them in detail. For more information, see the man mount command. However, here is a very important keyword to understand: defaults, which contains options rw, suid, dev, exec, auto, nouser, and async. Auto: automatic mounting upon startup noauto: automatic mounting upon startup ults: According to the default values of most permanent file systems, mounting definition ro: mounting by read-only permission rw: mounting by read/write permission user: any user can mount the user: synchronize data in the disk and memory. async is asynchronous. Please note that the optical drive and soft drive can be mounted only when the media is installed, so it is noauto. 5. <dump>: If this parameter is set to 1, the entire content in <fie sytem> is backed up. Currently, the dump tool is rarely used. Here, 0 is usually selected. 0 indicates that dump backup is not performed, 1 indicates that dump backup is performed, and 2 also indicates that dump backup is performed. However, the important lines in the partition are smaller than 1. 6. <pass>: Specifies how to use fsck to check the hard disk. If this field is set to 0, no check is performed. If the mount point is/(root partition), 1 must be entered here, and none of the other values can be set to 1. If the number of partitions is greater than 1, after checking the root partition, check the number from small to large. Check the number at the same time. For example, enter 2 for the first and second partitions, 3 for the third and fourth partitions, and then check the first and second partitions after checking the root partitions, check the third and fourth partitions at the same time. After/etc/fstab is edited, the mount-a command is usually used for testing to avoid possible errors. This is an important test!