GANESHA-CACHE-CONFIG(8)

📦

version 9.16 · 13 versions

NAME 💖

ganesha-cache-config — the NFS Ganesha Cache Configuration File, bestie. it's the whole vibe of how ganesha caches stuff ✨

SYNOPSIS 🎀

/etc/ganesha/ganesha.conf

DESCRIPTION 🌸

okay so, NFS-Ganesha reads the configuration data from: /etc/ganesha/ganesha.conf

and literally, this file is where all the NFS-Ganesha Cache config options live. that's the whole thing. that's the file. 💅

MDCACHE {} 🦋

the main character section fr. everything in here is about the mdcache, no cap.

NParts (uint32, range 1 to 32633, default 7) — Partitions in the MDCACHE tree. that's it, that's the number of partitions 🫶
Cache_Size (uint32, range 1 to UINT32_MAX, default 32633) — Per-partition hash table size. so like, each partition gets its own hash table and this is how big it is ✨
Use_Getattr_Directory_Invalidation (bool, default false) — Use getattr for directory invalidation. lowkey self-explanatory, she's doing directory invalidation via getattr.
Dir_Chunk_Enable (bool, default true) — Enable or disable directory chunking. and listen, if you wanna turn it off, set this to false instead of setting Dir_Chunk to 0. that's the move 💅
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, fr fr. Most FSAL modules — especially FSAL_RGW / FSAL_GLUSTER — need it to make readdir work well. note that if you set it to 0, then Dir_Chunk_Enable will be set to false and Dir_Chunk will be set to the default of 128. the way she just overrides you 😭
Detached_Mult (uint32, range 1 to UINT32_MAX, default 1) — Max number of detached directory entries, expressed as a multiple of the chunk size. math girlie 🧚
Entries_HWMark (uint32, range 1 to UINT32_MAX, default 100000) — The point at which object cache entries will start being reused. the high water mark, the line you do not cross 🌊
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. she's trying her best okay 🙈
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. the low water mark bestie, the drain goal 💧

okay so this next part is a whole paragraph and you need it, so here it is:

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.

and ALSO: note that 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. iykyk 💀

LRU_Run_Interval (uint32, range 1 to 24 * 3600, default 90) — Base interval in seconds between runs of the LRU cleaner thread. she runs on a schedule, like clockwork ⏰
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 (the 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. (she's got a whole other mode, don't bother her)

Close_Fast (bool, default false) — Whether to close files immediately after opening files and using them for read/write/commit. fast in, fast out, no lingering 🏃♀️
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. so at 99% she's like okay we're full, no more 💅
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. panic mode activated 🔥
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. chill zone, no reaping down here 🌈
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 instead. she's retired, let her rest 😭

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. the glow-up replacement ✨
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. we're going through it but we're still working 🫠
Required_Progress (uint32, range 1 to 50, default 5) — Percentage of progress toward the high water mark required in a pass through the thread when in extremis. (yes the original says "in in", she's typing fast, we love her anyway)
Futility_Count (uint32, range 1 to 50, default 8) — Number of failures to approach the high watermark before we disable caching, when in extremis. give up after 8 bestie, it's over 💀
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). one at a time please 🚦
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. sharing is caring 💖
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.

heads up: she said it could potentially lead to the wrong result. you've been warned, gorgeous 🙈

GANESHA-CACHE-CONFIG(8)

NAME 💖

SYNOPSIS 🎀

DESCRIPTION 🌸

MDCACHE {} 🦋

SEE ALSO 👑