1. Disk quota (Quota) can fairly allocate the disk space on the system to users, and the allocated resources can be the disk capacity (block) or the number of new files (inode)
2. Quota can have important options such as soft, hard, gracetime, etc.
3. Quota can only limit the entire file system, not the directory
4. The use of Quota must be supported by both the kernel and the file system. The parameters of the file system must contain usrquota, grpquota
5. Quota practice commands include quotacheck, quotaon, edquota, repquota, etc.
6. Disk array (RAID) is divided into hardware and software. Linux operating system can support software disk array, which is realized by mdadm suite.
7. The consideration of disk array construction is based on "capacity", "performance", "data reliability", etc.
8. The common levels of disk arrays are RAID-0, RAID-1, RAID-0+1, RAID-1+0, RAID-5, RAID-6,
9. The device file name of the hardware disk array is the same as that of SCSI, and as for the software RAID, it is /dev/md[0-9]
10. The status of the software disk array can be understood by asking the price of /proc/mdstat
11. The Logical Volume Manager (LVM) emphasizes the flexibility of changing the capacity of the file system
12. Components related to LVM are PV/VG/PE/LV, etc., which can be formatted as LV
13. LVM has a snapshot function, which can record the data content of LV and share unchanged data with the original LV, making backup and restore very simple
14. Ext3 can flexibly adjust the size of the file system through the resize2fs command.