Linux 124 Lesson 14, accessing the Linux file system

, identify file system hierarchies
Storage device--block device/storage location dev/

Disk naming rules, when the system checks for physical devices
　　
SCSI/STAT/USB First Disk/DEV/SDA
Second hard drive/dev/sdb
　　
Virtual Disk/dev/vda/dev/vdb
　　
Fdisk-l View all disks
/dev/sda
/DEV/SDA1 First partition on first disk
/DEV/SDB3 a third partition on the second disk
　　
Df-h T System File system specific information, you can view the Mount situation
Du-h/etc/View disk footprint
　　
2. Mount and unmount the file system
Partition capacity is still unusable and must be mounted if it is allocated and not mounted
　　
To access a disc:
Df-ht you can see the location of the inserted disc, you can view the default mount point
　　
The default mount point is not saved after a reboot, and you need to manually create a mount point to mount
Disc Type: iso9660
Default location:/dev/sr0/dev/cdrom
　　
(1) Temporary mounting
Mount-t iso9660/dev/sro0/mnt
　　
umount/mnt/If you cannot uninstall using the lsof command to view the process
LSOF/MNT See which process is consuming the/mnt/file
Kill-9 1517 kills 1517 processes, then unloads

(2) Permanent mount, import into config file, still valid after reboot
Vim/etc/fstab
/DEV/SR0 (uuid available)/mnt iso9660 defaults 0 0
　　
UUID through a unique identification code
Blkid See UUID
　　
Mount-a Find Fstab
　　
Mount the hard drive,
Partitioning and formatting of disks in the 134 course
　　
Lab FS Setup Instructional scripts
Rht-vmctl Fulreset Server
　　
Vim/etc/fstab
Uuid= ""/disk1 xfs defaults 0 0
Mount-a
　　
3. Use hard links and symbolic links
　　
Hard Links:
(1) When the data is stored, it has the same inode node, but stores two copies of the same data;
Sector 512 bytes Data is stored in the smallest unit of block 8 sectors for a fast (4 bytes)
Meta information (creator, creation date, size) stored in Inode node (index node)
Ll-li I view inode nodes
　　
Touch File1
echo Date >file1
ln file1/tmp/file1 Creating a hard link
　　
Ll-li/file1
Ll-li/tmp/file1
　　
Hard links cannot be implemented across regions;
Use Inode data from one disk
　　
Cannot make hard links to directories;

Soft Links: Shortcuts
　　
Ln-s/usr/local AA
　　
Ll-li/usr/local
Ll-li/root/aa
If the source file is deleted, the linked file fails

One file changes and the other changes

(4) You can make a soft link to the directory
　　
Usage Scenario: Hard Link: Data backup

4. Search for files in the file system
(1) Locate find data in locate database, locate data need to be refreshed manually
　　
Touch File1
cd/tmp/
The newly created file, which is not written to the locate database, requires a manual update of the database UpdateDB
　　
UpdateDB

Find/tmp-name File2
Find/-USESR Student
Find/-type L
Find/-perm 777
Find/-size +100m
Find/-mmin 30
Find/-exec Execute next command
Find/-user student-exec scp-rf {}/tmp/\;
　　
Force recursion {} represents the previous search result

Linux 124 Lesson 14, accessing the Linux file system