Disk Accounting

Disk accounting enables you to gather and format the following data about the files each user has on disks:

• Name and ID of the user

• Number of blocks used by the user's files

This data is collected by the shell script /usr/lib/acct/dodisk at intervals determined by the entry you add to the /var/spool/cron/crontabs/root file. In turn, dodisk invokes the commands acctdusg and diskusg, which gather disk usage by login.

See "How to Set Up System Accounting" for more information about setting up dodisk.

The acctdusg(1M) command gathers all the disk accounting information. Each time it is invoked, this command can process a maximum of 3000 users.

Information gathered by running dodisk(1M) is stored in the /var/adm/acct/nite/disktacct file. This information is overwritten the next time dodisk is run. Therefore, avoid running dodisk twice in the same day.

The diskusg command may overcharge for files that are written in random access fashion, which may create holes in the files. This is because diskusg does not read the indirect blocks of a file when determining its size. Rather, diskusg determines the size of a file by looking at the di_size value of the inode.