AdvFS Filesets and File Systems

AdvFs supports a tree directory of filesets inside file domains. Filesets support clone filesets, that are read-only copies of existing filesets created to capture data at one moment in time. AdvFS supports multivolume file domains.
Use the following guidelines for filesets:

• The number of filesets mounted simultaneously is limited to 512 minus the number of active file domains.

• The number of filesets per domain depends on site requirements. Filesets are managed independently of each other (mount, backup, and quotas).

Refer to advfs(4), fdmns(4), mkfset(8), and showfsets(8) for more information.

AdvFS always attempts to write each file to disk as a set of contiguous units called pages and sized 8 KB of disk space. A set of one or more contiguous pages is called an extent.

AdvFS adds pages to the file by preallocating disk space, that is truncated when the file is close. Unused preallocated space is available for the next write.

AdvFs implements a special fragmentation policy. To reduce fragmentation run periodically the defragment utility. See defragment(8) reference page for more information.