Veritas File System 4.1 Release Notes (5900-0592, March 2010)

• Storage Checkpoint File System Restore
Storage Checkpoints can be used for backing up and restoring individual files, applications
or an entire file system. Restoring from Storage Checkpoints can recover data from incorrectly
modified files, but cannot be used to recover data lost due to hardware damage or other file
system integrity problems. File system restoration can be done using the fsckpt_restore (1M)
administrative command. See ““Product Licensing (Currently not available)”? for more
information on licensing support for this feature.
The following new command is associated with this feature:
fsckpt_restore The fsckpt_restore restores a VxFS file system on the block device
device_name from one of its Storage Checkpoints ckpt_name.
• File Change Log
The VxFS File Change Log (FCL) tracks changes to files and directories in a file system. The
File Change Log can be used by applications such as backup products, webcrawlers, search
and indexing engines, and replication software that typically scan an entire file system
searching for modifications since the last scan. See ““Product Licensing (Currently not
available)”? for more information on licensing support for this feature.
The following command is associated with FCL:
fcladm The fcladm command performs online administration functions for the Veritas
File system FCL feature.
The following new tunable parameters are associated with FCL:
fcl_keeptime Specifies the minimum amount of time for which FCL keeps records
in the log.
fcl_maxalloc Specifies the maximum amount of space that can be allocated to the
FCL.
fcl_winterval Specifies the interval that must elapse before the FCL records are
written to a file.
See vxtunefs (1M) for more information on tunable parameters.
The File Change Log feature includes the application programming interface (API)
vxfs_fcl_sync that sets a synchronization point in the File Change Log.
• Named Data Streams
The named data streams feature allows a single inode to be attached with multiple data
streams. In VxFS 4.1, new data streams are referenced through a new directory inode
associated with the file. Each directory inodes point to a new inode, one per stream. The
directory containing the named streams is not directly visible to the user.
The following application programming interface (API) functions are associated with the
named data streams functions:
vxfs_nattr_link The vxfs_nattr_link() function creates a new directory
entry for an existing named data stream and, increments its link
count by one.
vxfs_nattr_open The vxfs_nattr_open() function renames a named data
stream.
vxfs_nattr_rename The vxfs_nattr_rename() function changes the name space
entry for the argument new of the file specified in the argument
sfd from the attribute old.
vxfs_nattr_unlink The vxfs_nattr_unlink() function removes the directory
entry for the named data stream pointed to by the path associated
with the file descriptor fd and, decrements the link count of the
associated named data stream by one.
12 Veritas File System 4.1 Release Notes