===================================================================
ganesha-cache-config -- NFS Ganesha Cache Configuration File
===================================================================

.. program:: ganesha-cache-config


SYNOPSIS
==========================================================

| /etc/ganesha/ganesha.conf

DESCRIPTION
==========================================================

NFS-Ganesha reads the configuration data from:
| /etc/ganesha/ganesha.conf

This file lists NFS-Ganesha Cache config options.

MDCACHE {}
--------------------------------------------------------------------------------

NParts (uint32, range 1 to 32633, default 7)
    Partitions in the MDCACHE tree.

Cache_Size(uint32, range 1 to UINT32_MAX, default 32633)
    Per-partition hash table size.

Use_Getattr_Directory_Invalidation(bool, default false)
    Use getattr for directory invalidation.

Dir_Chunk_Enable(bool, default true)
    Enable or disable directory chunking. Set this false in preference to
    setting Dir_Chunk to 0.

Dir_Chunk(uint32, range 0 to UINT32_MAX, default 128)
    Size of per-directory dirent cache chunks, 0 means directory chunking is not
    enabled. Dir_Chunk should always be enabled. Most FSAL modules especially
    FSAL_RGW/FSAL_GLUSTER need it to make readdir work well.
    Note that if set to 0, Dir_Chunk_Enable will be set to false and Dir_Chunk
    will be set to the default of 128.

Detached_Mult(uint32, range 1 to UINT32_MAX, default 1)
    Max number of detached directory entries expressed as a multiple of the
    chunk size.

Entries_HWMark(uint32, range 1 to UINT32_MAX, default 100000)
    The point at which object cache entries will start being reused.

Entries_Release_Size(uint32, range 0 to UINT32_MAX, default 100)
    The number of entries attempted to release each time when the handle
    cache has exceeded the entries high water mark.

Chunks_HWMark(uint32, range 1 to UINT32_MAX, default 1000)
    The point at which dirent cache chunks will start being reused.

Chunks_LWMark(uint32, range 1 to UINT32_MAX, default 1000)
    The target for reaping dirent cache chunks to drain the cache.

    Entries_HWMark, Dir_Chunk, Chunks_HWMark, Chunks_LWMark all play together.
    While a dirent chunk is cached, the object cache entries that are part of
    that dirent chunk will be retained in the cache indefinitely. Note that
    this means that possibly Chunks_LWMark * Dir_Chunk entries will be retained.
    If this is larger than Entries_HWMark, then the object cache may end up
    remaining above Entries_HWMark for a significant time. Consider the average
    size of the directories and the number of directories desired to be
    maintained in the cache and set Chunks_LWMark appropriately.

    Note that the Chunks_LWMark defaults to the same value as Chunks_HWMark
    and these are set to 1/100 of Entries_HWMark suggesting an average directory
    size of 100. It may be desirable to set Chunks_LWMark less than Chunks_HWMark
    if it is desirable to allow large directory chunks to not immediately be
    re-used, but it is desirable to in the short term drain the dirent cache
    down to a smaller number.

LRU_Run_Interval(uint32, range 1 to 24 * 3600, default 90)
    Base interval in seconds between runs of the LRU cleaner thread.

Cache_FDs(bool, default true)
    If "Cache_FDs" is set to false, the reaper thread aggressively
    closes FDs , significantly reducing the number of open FDs.
    This will help to maintain a minimal number of open FDs.

    If "Cache_FDs" is set to true (default), FDs are cached, and the
    LRU reaper thread closes FDs only when the current open FD count
    reaches or exceeds the "fds_lowat" threshold.

    Note, this setting has no effect when Close_Fast is set to true.

Close_Fast(bool, default false)
    Whether to close files immediately after opening files and using them for
    read/write/commit.

FD_Limit_Percent(uint32, range 0 to 100, default 99)
    The percentage of the system-imposed maximum of file descriptors at which
    Ganesha will deny requests.

FD_HWMark_Percent(uint32, range 0 to 100, default 90)
    The percentage of the system-imposed maximum of file descriptors above which
    Ganesha will make greater efforts at reaping.

FD_LWMark_Percent(uint32, range 0 to 100, default 50)
    The percentage of the system-imposed maximum of file descriptors below which
    Ganesha will not reap file descriptors.

Reaper_Work(uint32, range 1 to 2000, default 0)
    Roughly, the amount of work to do on each pass through the thread under
    normal conditions.  (Ideally, a multiple of the number of lanes.)  *This
    setting is deprecated.  Please use Reaper_Work_Per_Lane*

Reaper_Work_Per_Lane(uint32, range 1 to UINT32_MAX, default 50)
    This is the number of handles per lane to scan when performing LRU
    maintenance.  This task is performed by the Reaper thread.

Biggest_Window(uint32, range 1 to 100, default 40)
    The largest window (as a percentage of the system-imposed limit on FDs) of
    work that we will do in extremis.

Required_Progress(uint32, range 1 to 50, default 5)
    Percentage of progress toward the high water mark required in in a pass
    through the thread when in extremis

Futility_Count(uint32, range 1 to 50, default 8)
    Number of failures to approach the high watermark before we disable caching,
    when in extremis.

Dirmap_HWMark(uint32, range 1 to UINT32_MAX, default 10000)
    The point at which dirmap entries are reused.  This puts a practical limit
    on the number of simultaneous readdirs that may be in progress on an export
    for a whence-is-name FSAL (currently only FSAL_RGW)

Files_Delegatable_Percent(int32, range 10 to 90, default 90)
    Total number of files ganesha can delegate to clients as a percent of
    Entries_HWMark

Use_Cached_Owner_On_Owner_Override(bool, true)
    This option allows mdcache_test_access to use the cached owner value
    for an object in case of owner override, even if the cache entry is
    not up to date. This could potentially lead to the wrong result, but
    can significantly improve performance saving the need to update
    attributes on many read/write operations.

See also
==============================
:doc:`ganesha-config <ganesha-config>`\(8)
