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  1. Agustin's Linux Manual
  2. System Administration
  3. About the Author
  4. Contents
  5. Administration
  6. Terminals
  7. Command Basics
  8. Root Directory
  9. Executing Commands
  10. File specs
  11. File Permission
  12. How permissions are assigned
  13. Change ownership chown
  14. Running multiple commands
  15. Killing Processes
  16. Bash configuration files
  17. VI Editor
  18. Creating path environment
  19. Midnight Commander
  20. Linuxconf Utility
  21. Networking
  22. Domain Name Service DNS
  23. Router and Gateway
  24. Adding Users
  25. User Accounts
  26. Managing Groups
  27. Mounting File System
  28. NFS Mounts
  29. Disk Quotas
  30. Run levels
  31. Linuxconf Control
  32. Mandrake Control Center
  33. Creating a Boot Disk
  34. Switching Boot Mode
  35. Hardware Configurations
  36. Printer Configuration
  37. Installing Printers
  38. Samba Printer
  39. Managing services
  40. Managing Users
  41. Program Scheduler
  42. Software Management
  43. Installing CUPS

Implementing disk quotas

Quotas are used to manage storage in distributed environments. Disk quotas are abilities to manage and limit disk resources to those who abuse the system in the form of storage facility.

Disk quotas allow you to monitor the amount of disk space left against the limit assigned to individual users or groups. Disk quotas can be controlled by per volume, per user and per group. If you suspect that a particular user is using disk space to download files from the Internet and is consuming a considerable amount of space… limit their space with quotas.

Note. My advice is not to assign individual quotas, especially if you have hundreds of users in your server. That will lead to administrative nightmares. Set quotas for individuals only when there is a compelling reason to do so.

Set quotas default is not the best way to set quotas; however you can use this option to set quotas for default user and default group. Before you can set quotas, a partition or volume must be quota enabled in the local access option.

File systems => Access local drive => Select and click on a partition => Options => User quota enabled.

After the partition's quota is enabled, quotas will be available in any part, such as in user accounts and group definitions.

User Information
Fig. 3.28

In the user property the quota is enabled per user The following is the group's property setting, very similar to the user's property.

The quotas are set in Mega Bytes. All quotas assigned to a group will be applied to all members in that group.

User Information
Fig. 3.29

Soft limit: the soft limit is a time limit set by the administrator. Users can exceed the soft limits assigned to them, but only for a limited amount of time--the time limit set by the administrator.

Grace period: This is governing the soft limit. When grace period is set; it acts as a borderline and times out. When a user reaches soft limit, grace period sent a warning to the user indicating that his limit is in violation.

Hard Limit: The hard limit represents an absolute limit on the resource, blocks or inodes, which the user can never exceed under any circumstances.

Effect of quotas on users

The following are the major effects of quotas on users:

  • On soft limit, if a user exceeds the space limit (blocks or inodes), the timer is started. If the user then reduces usage, the timer is turned off and all returns to normal. But if the user has not reduced usage when the timer expires, any further attempts to acquire space resources fails, and the user receives error messages saying that the file system is full. These messages persist until the user reduces usage under the soft limit level.
  • If a user reaches the hard limit at any time, the system will warn the user that there is not enough space and will automatically lock the space usage.