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

Parameters

The following is the syntax for the vxfs_fcl_seektime() function:

int vxfs_fcl_seektime(void *handle, struct fcl_timeval time)

The function parameters are as follows:

  • *handle is a valid handle returned by a previous call to vxfs_fcl_open

  • time is an fcl_time_t structure type defined as follows:

    struct fcl_time {
    uint32_t tv sec;
    unit32_t tv_nsec;
} fcl_time t;

    Note:

    The time specified in fcl_time_t is in seconds or nanoseconds, while the time that is returned by a standard system call such as gettimeofday may be in seconds or microseconds. Therefore, a conversion may be needed.

vxfs_fcl_seektime assumes that the entries in the FCL are in a non-decreasing order of the time-stamps and does a faster-than-linear (binary) search to determine the FCL record with a time-stamp greater than the specified time. This means that vxfs_fcl_seektime can seek to a different record when compared to a seek done through a linear search. As a result, the vxfs_fcl_seektime interface is not 100% reliable.

The time-stamps in the FCL might be out-of-order under the following circumstances:

  • If the system time is modified

  • If the FCL file is on a cluster-mounted file system and the times on the different nodes are out-of-sync

Warning:

On a cluster file system, you must use a mechanism to keep the system clocks in sync (for example, Network Time Protocol - NTP), to help ensure that the vxfs_fcl_seektime interface is kept reasonably accurate.