A quotas file (named
quotas) must exist in the root directory of a file system for any of the quota commands to work. The files in the file system's mount point are referred to as the external quotas file. VxFS also maintains an internal quotas file for its own use.
The quota administration commands read and write to the external
quotas file to obtain or change usage limits. VxFS uses the internal file to maintain counts of data blocks and inodes used by each user. When quotas are turned on, the quota limits are copied from the external
quotas file into the internal
quotas file. While quotas are on, all the changes in the usage information and changes to quotas are registered in the internal
quotas file. When quotas are turned off, the contents of the internal
quotas file are copied into the external
quotas file so that all data between the two files is synchronized.