clonefset - Creates a read-only copy of a fileset
/usr/sbin/clonefset domain fileset clonename
Specifies the name of an existing domain. Specifies the name of the original fileset that the clonefset utility will clone. Specifies the name of the read-only fileset created by the clonefset utility.
The clonefset utility enables you to perform online backups of active files by making a read-only copy (clone) of an active fileset. Once you create and mount a clone fileset, you can back up the clone using the vdump command or other supported backup utility (the dump command is not supported by AdvFS). Note that the clonefset utility only clones AdvFS filesets; it does not clone UFS file systems.
A clone fileset is a read-only snapshot of fileset data structures (metadata). When you clone a fileset, the utility copies only the structure of the original fileset, not its data. When you modify files in the original fileset, the file system copies the original pages to the clone fileset. In this way, the clone fileset contents remain the same as when you first created it.
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 rmfset command. Note
You must have root privilege to access this utility. Additionally, you must register the Advanced File System Advanced Utilities license to use this utility.
Do not create and mount 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 the following message to 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.00027192.00000001.8001 WARNING: file id = 00000001.8001 This message also appears in the /var/adm/syslog.dated/latest_boot_date/kern.log file.
The following example creates a read-only copy of the credit_fs fileset that resides in the accounts_dmn file domain. The clone fileset name in this example is credit_clone1. This example also performs an online backup and removes the clone fileset after the backup is complete:
# mkdir /mnt/credit_clone1 # clonefset accounts_dmn credit_fs credit_clone1 # mount -t advfs account_dmn#credit_clone1 /mnt/credit_clone1 # vdump /mnt/credit_clone1 # umount /mnt/credit_clone1 # rmfset account_dmn credit_clone1
advfs(4), showfdmn(8), tar(8), vdump(8), vrestore(8).