PRIMECLUSTER Global File Services Configuration and Administration Guide 4.2 (Solaris(TM) Operating Environment)

7.2 quota Management Method for GFS Local File System

To manage the limit values, number of usage files, and number of usage blocks for each general user, the UFS quota function uses a quotas file in the root directory of the file system. In the GFS Local File System, a quotas file hidden in the file system, called an external quotas file, is used in addition to the above quotas file, called an internal quotas file. The external quotas file is used to manage the limit values for each general user. The internal quotas file is used to manage the limit values, number of usage files, and number of usage blocks for each general user.

Using two files to manage the usage of general users has the following benefits:

• Even if a command such as the rm(1) command deletes the external quotas file by mistake, the internal quotas file remains. As a result, quota data does not have to be set up again or matched. In addition, the external quotas file can easily be restored from the internal quotas file.
• Because the external quotas file manages only the limit values, the number of usage files or blocks is not changed if the external quotas file is backed up or restored during operation. As a result, quota data does not have to be matched.
• Update data in the internal quotas file is written to the update log area. As a result, the integrity of the file system can be quickly restored in the event of a system failure.