summaryrefslogtreecommitdiffstats
path: root/include/linux/nfs_iostat.h
blob: 8866bb3502ee1df94075aa2068a980cb7fe2f090 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/*
 *  User-space visible declarations for NFS client per-mount
 *  point statistics
 *
 *  Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com>
 *
 *  NFS client per-mount statistics provide information about the
 *  health of the NFS client and the health of each NFS mount point.
 *  Generally these are not for detailed problem diagnosis, but
 *  simply to indicate that there is a problem.
 *
 *  These counters are not meant to be human-readable, but are meant
 *  to be integrated into system monitoring tools such as "sar" and
 *  "iostat".  As such, the counters are sampled by the tools over
 *  time, and are never zeroed after a file system is mounted.
 *  Moving averages can be computed by the tools by taking the
 *  difference between two instantaneous samples  and dividing that
 *  by the time between the samples.
 */

#ifndef _LINUX_NFS_IOSTAT
#define _LINUX_NFS_IOSTAT

#define NFS_IOSTAT_VERS		"1.0"

/*
 * NFS byte counters
 *
 * 1.  SERVER - the number of payload bytes read from or written
 *     to the server by the NFS client via an NFS READ or WRITE
 *     request.
 *
 * 2.  NORMAL - the number of bytes read or written by applications
 *     via the read(2) and write(2) system call interfaces.
 *
 * 3.  DIRECT - the number of bytes read or written from files
 *     opened with the O_DIRECT flag.
 *
 * These counters give a view of the data throughput into and out
 * of the NFS client.  Comparing the number of bytes requested by
 * an application with the number of bytes the client requests from
 * the server can provide an indication of client efficiency
 * (per-op, cache hits, etc).
 *
 * These counters can also help characterize which access methods
 * are in use.  DIRECT by itself shows whether there is any O_DIRECT
 * traffic.  NORMAL + DIRECT shows how much data is going through
 * the system call interface.  A large amount of SERVER traffic
 * without much NORMAL or DIRECT traffic shows that applications
 * are using mapped files.
 *
 * NFS page counters
 *
 * These count the number of pages read or written via nfs_readpage(),
 * nfs_readpages(), or their write equivalents.
 *
 * NB: When adding new byte counters, please include the measured
 * units in the name of each byte counter to help users of this
 * interface determine what exactly is being counted.
 */
enum nfs_stat_bytecounters {
	NFSIOS_NORMALREADBYTES = 0,
	NFSIOS_NORMALWRITTENBYTES,
	NFSIOS_DIRECTREADBYTES,
	NFSIOS_DIRECTWRITTENBYTES,
	NFSIOS_SERVERREADBYTES,
	NFSIOS_SERVERWRITTENBYTES,
	NFSIOS_READPAGES,
	NFSIOS_WRITEPAGES,
	__NFSIOS_BYTESMAX,
};

/*
 * NFS event counters
 *
 * These counters provide a low-overhead way of monitoring client
 * activity without enabling NFS trace debugging.  The counters
 * show the rate at which VFS requests are made, and how often the
 * client invalidates its data and attribute caches.  This allows
 * system administrators to monitor such things as how close-to-open
 * is working, and answer questions such as "why are there so many
 * GETATTR requests on the wire?"
 *
 * They also count anamolous events such as short reads and writes,
 * silly renames due to close-after-delete, and operations that
 * change the size of a file (such operations can often be the
 * source of data corruption if applications aren't using file
 * locking properly).
 */
enum nfs_stat_eventcounters {
	NFSIOS_INODEREVALIDATE = 0,
	NFSIOS_DENTRYREVALIDATE,
	NFSIOS_DATAINVALIDATE,
	NFSIOS_ATTRINVALIDATE,
	NFSIOS_VFSOPEN,
	NFSIOS_VFSLOOKUP,
	NFSIOS_VFSACCESS,
	NFSIOS_VFSUPDATEPAGE,
	NFSIOS_VFSREADPAGE,
	NFSIOS_VFSREADPAGES,
	NFSIOS_VFSWRITEPAGE,
	NFSIOS_VFSWRITEPAGES,
	NFSIOS_VFSGETDENTS,
	NFSIOS_VFSSETATTR,
	NFSIOS_VFSFLUSH,
	NFSIOS_VFSFSYNC,
	NFSIOS_VFSLOCK,
	NFSIOS_VFSRELEASE,
	NFSIOS_CONGESTIONWAIT,
	NFSIOS_SETATTRTRUNC,
	NFSIOS_EXTENDWRITE,
	NFSIOS_SILLYRENAME,
	NFSIOS_SHORTREAD,
	NFSIOS_SHORTWRITE,
	NFSIOS_DELAY,
	NFSIOS_PNFS_READ,
	NFSIOS_PNFS_WRITE,
	__NFSIOS_COUNTSMAX,
};

/*
 * NFS local caching servicing counters
 */
enum nfs_stat_fscachecounters {
	NFSIOS_FSCACHE_PAGES_READ_OK,
	NFSIOS_FSCACHE_PAGES_READ_FAIL,
	NFSIOS_FSCACHE_PAGES_WRITTEN_OK,
	NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL,
	NFSIOS_FSCACHE_PAGES_UNCACHED,
	__NFSIOS_FSCACHEMAX,
};

#endif	/* _LINUX_NFS_IOSTAT */