advfs_clonefset(3) Library Functions Manual advfs_clonefset(3)
NAME
advfs_clonefset - Creates a read-only copy of an active fileset
SYNOPSIS
#include <sys/advfs_syscalls.h>
int advfs_clonefset(
char *domain,
char *fileset,
char *clonename );
LIBRARY
AdvFS Library (libadvfs)
PARAMETERS
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.
DESCRIPTION
This function makes a read-only copy (clone) of an active fileset without 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 original fileset at the time you created the clone.
You can form a fileset backup strategy by managing clone filesets without ever needing to take the original filesets off line. For exam-
ple, 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.
NOTES
This function has features identical to the utility described in clonefset(8).
RESTRICTIONS
This function only clones AdvFS filesets; it does not clone UFS file systems.
The program that calls this function must be running with root privilege.
A fileset must have a unique name of up to 31 characters. All whitespace 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 consistency 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/latest_boot_date/kern.log file.
RETURN VALUES
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.
ERRORS
The function sets errno to the specified errors for the following failure conditions: A valid AdvFS Advanced Utilities license is not
installed.
The calling program is not running with root privileges. The AdvFS lock for domain could not be acquired because one of the follow-
ing 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.
SEE ALSO
Commands: clonefset(8), mkfset(8), rmfset(8), showfsets(8)
Functions: advfs_rmfset(3)
advfs_clonefset(3)