Veritas™ File System Programmer's Reference Guide - Solaris

Last Published:
Product(s): InfoScale & Storage Foundation (7.2)
Platform: Solaris
  1. Veritas File System software developer's kit
    1.  
      About the software developer's kit
    2. File System software developer's kit features
      1.  
        API library interfaces
      2.  
        File Change Log
      3.  
        Multi-volume support
      4.  
        Veritas File System I/O
    3.  
      Software developer's kit packages
    4.  
      Required libraries and header files
    5. Compiling environment
      1.  
        Recompiling with a different compiler
  2. File Change Log
    1. About the File Change Log file
      1.  
        Recorded changes
      2. Using the File Change Log file
        1.  
          Space usage
        2.  
          Full system scan reductions
        3.  
          File history traces
      3.  
        File Change Log logging activation
      4. File Change Log file layout
        1.  
          File Change Log superblock
        2.  
          File Change Log record
    2. Record types
      1.  
        Special records
      2.  
        Typical record sequences
    3. File Change Log tunables
      1.  
        How tunables handle File Change Log growth size
    4. Application programming interface for File Change Log
      1.  
        Ease of use
      2.  
        Backward compatibility
      3. API functions
        1.  
          Functions for accessing File Change Log records
        2.  
          Functions for seeking offsets and time stamps in the File Change Log
        3. vxfs_fcl_open
          1.  
            Return value
        4. vxfs_fcl_close
          1.  
            Parameters
        5. vxfs_fcl_getinfo
          1.  
            Return values
        6. vxfs_fcl_read
          1.  
            Parameters
          2.  
            Input
          3.  
            Output
          4.  
            Return values
        7. vxfs_fcl_getcookie
          1.  
            Parameters
        8. vxfs_fcl_seek
          1.  
            Parameters
          2.  
            Return values
        9. vxfs_fcl_seektime
          1.  
            Parameters
          2.  
            Return values
        10. vxfs_fcl_sync
          1.  
            Parameters
      4. File Change Log record
        1.  
          Defines
        2.  
          fcl_iostats structure
        3.  
          fcl_acsinfo structure
        4.  
          Record structure fields
      5. Copying File Change Log records
        1.  
          Index maintenance application
        2. Computing a usage profile
          1.  
            Initial setup
          2.  
            Sample steps
          3.  
            Off host processing
      6. Veritas File System and File Change Log upgrade and downgrade
        1.  
          Converting File Change Log version 3 files to version 4
        2.  
          Downgrading Veritas File System versions
    5. Reverse path name lookup
      1.  
        Inodes
      2.  
        vxfs_inotopath_gen
  3. Multi-volume support
    1.  
      About multi-volume support
    2.  
      Uses for multi-volume support
    3. Volume application programming interfaces
      1.  
        Administering volume sets
      2.  
        Querying the volume set for a file system
      3.  
        Modifying a volume within a file system
      4.  
        Encapsulationg and de-encapsulating a volume
    4. Allocation policy application programming interfaces
      1.  
        Directing file allocations
      2.  
        Creating and assigning policies
      3.  
        Querying the defined policies
      4.  
        Enforcing a policy
    5.  
      Data structures
    6. Using policies and application programming interfaces
      1.  
        Defining and assigning allocation policies
      2.  
        Using volume application programming interfaces
  4. Named data streams
    1.  
      About named data streams
    2.  
      Uses for named data streams
    3.  
      Named data streams application programming interface
    4.  
      Listing named data streams
    5.  
      Namespace for named data streams
    6.  
      Behavior changes in other system calls
    7.  
      Querying named data streams
    8.  
      Application programming interface
    9.  
      Command reference
  5. Veritas File System I/O
    1.  
      About Veritas File System I/O
    2.  
      Freeze and thaw
    3. Caching advisories
      1.  
        Direct I/O
      2.  
        Concurrent I/O
      3.  
        Unbuffered I/O
      4.  
        Other advisories
    4. Extents
      1. Extent attributes
        1.  
          Attribute specifics
      2.  
        Reservation: preallocating space to a file
      3.  
        Fixed extent size
      4.  
        Application programming interface for extent attributes
      5. Allocation flags
        1.  
          Allocation flags with reservation
        2.  
          Reservation trimming
        3.  
          Non-persistent reservation
        4.  
          No write beyond reservation
        5.  
          Contiguous reservation
        6.  
          Include reservation in the file size
        7.  
          Reading the grown part of the file
      6.  
        Allocation flags with fixed extent size
      7.  
        How to use extent attribute APIs
      8.  
        Setting fixed extent size
  6. Thin Reclamation
    1.  
      About Thin Storage
    2.  
      About Thin Reclamation
    3. Thin Reclamation application programming interface
      1.  
        vxfs_ts_reclaim return values

Attribute specifics

There are two extent attributes associated with a file: reservation and fixed extent size. You can preallocate space to the file by manipulating a file's reservation. You can also override the default allocation policy of the file system by setting a fixed extent size. Other policies determine the way these attributes are expressed during the allocation process.

You can specify the following:

  • The space reserved for a file must be contiguous

  • No allocations are made for a file beyond the current reservation

  • An unused reservation is released when the file is closed

  • Space is allocated, but no reservation is assigned

  • The file size is changed to immediately incorporate the allocated space

Some of the extent attributes are persistent and become part of the on-disk information about the file, while other attributes are temporary and are lost after the file is closed or the system is rebooted. The persistent attributes are similar to the file's permissions and are written in the inode for the file. When a file is copied, moved, or archived, only the persistent attributes of the source file are preserved in the new file.