advfs_clonefset(3)advfs_clonefset(3)NAMEadvfs_clonefset - Creates a read-only copy of an active fileset
char *clonename );
AdvFS Library (libadvfs)
Specifies the name of an existing AdvFS file domain. Specifies the
name of original fileset. Specifies the name of the read-only clone
fileset of the original fileset.
This function makes a read-only copy (clone) of an active fileset with‐
out taking the fileset off line.
When you create a clone fileset, it is a read-only snapshot of fileset
data structures (metadata). That is, when you clone a fileset only the
structure of the original fileset is copied, not its data. As time
goes by and as the files in the original fileset are modified, the file
system copies the original pages to the clone fileset. In this way, the
clone fileset preserves the contents of files as they were in the orig‐
inal fileset at the time you created the clone.
You can form a fileset backup strategy by managing clone filesets with‐
out ever needing to take the original filesets off line. For example,
you can determine when to unmount a clone, mount the clone on another
mount point, and then use the vdump command to back it up.
You can create new versions of a clone fileset, but you can maintain
only one clone per fileset at a time. You can remove an existing clone
fileset by using the advfs_rmfset function.
This function has features identical to the utility described in
This function only clones AdvFS filesets; it does not clone UFS file
The program that calls this function must be running with root privi‐
A fileset must have a unique name of up to 31 characters. All white‐
space characters (tab, new line, space, and so on) and the / # : * ?
characters are invalid for fileset names.
Do not create a clone fileset if the available disk space for the file
domain is less than 5 percent of the total. When a file domain runs out
of disk space, the file system loses its ability to maintain the con‐
sistency of files within clone filesets. When the file system can no
longer maintain consistency, it displays warning messages similar to
the following on the user's terminal and to the console: WARNING: advfs
cannot copy-on-write data to a clone file. WARNING: encountered the
following error: ENO_MORE_BLKS (-1040) WARNING: do not continue using
the clone fileset. WARNING: original file set: name=mnt,
id=2c06a73f.00027192.00000001.8001 WARNING: clone file set: name=clone,
id=2c06a73f.00027192.00000002.8002 WARNING: file id = 0000000a.8002
This message also appears in the /var/adm/syslog.dated/lat‐
The function returns a value of 0 (zero) on successful completion. The
function returns a value of -1 on failure and sets the value of errno
to the specific error.
The function sets errno to the specified errors for the following fail‐
ure conditions: A valid AdvFS Advanced Utilities license is not
The calling program is not running with root privileges. The
AdvFS lock for domain could not be acquired because one of the
following operations was already running on the domain: balance,
defragment, rmfset, or rmvol. The fileset you want to clone
already has an existing clone. The name of the clone contains
an invalid character or any of the parameters are NULL or set to
. An I/O error occurred on one of the disks in the file domain.
The name of the clone is longer than 31 characters. The file
domain specified by the domain parameter does not exist.
The fileset specified by the fileset parameter does not exist in
the file domain specified by the domain parameter. There is not
enough memory available for the operation. There is not enough
available space in the file domain to create a clone fileset.
Commands: clonefset(8), mkfset(8), rmfset(8), showfsets(8)