What:		/proc/fs/nfsd/reply_cache_stats
Date:		March 2013
KernelVersion:	3.10
Contact:	linux-nfs@vger.kernel.org
Description:
		Provides statistics for the NFS server duplicate reply
		cache (DRC). The file contains one labeled field per
		line. Each line has the form "field name:" followed by
		whitespace and a decimal value.

		Fields:

		=======================  ======  ==========================
		max entries              u32     Upper bound on cache size
		num entries              u32     Current entry count
		hash buckets             u32     Number of hash buckets
		mem usage                s64     Bytes consumed by the DRC
		cache hits               s64     Requests answered from cache
		cache misses             s64     Requests not found in cache
		not cached               s64     Idempotent requests that
		                                 bypass the cache
		payload misses           s64     XID matched but request
		                                 checksum did not
		longest chain len        u32     Longest hash chain observed
		cachesize at longest     u32     Cache size when longest
		                                 chain was recorded
		=======================  ======  ==========================

		Counter fields (cache hits, cache misses, not cached,
		payload misses, mem usage) are maintained with per-cpu
		counters and may briefly show stale values under
		concurrent load. There is no way to reset these
		counters; consumers should compute rates by sampling
		over time.

		New fields may be appended in future kernels. Parsers
		should match on field name, not line position.
Users:		nfs-utils (https://git.linux-nfs.org/?p=steved/nfs-utils.git)