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1/*
2 drbd_limits.h
3 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
4*/
5
6/*
7 * Our current limitations.
8 * Some of them are hard limits,
9 * some of them are arbitrary range limits, that make it easier to provide
10 * feedback about nonsense settings for certain configurable values.
11 */
12
13#ifndef DRBD_LIMITS_H
14#define DRBD_LIMITS_H 1
15
16#define DEBUG_RANGE_CHECK 0
17
18#define DRBD_MINOR_COUNT_MIN 1
19#define DRBD_MINOR_COUNT_MAX 255
20
21#define DRBD_DIALOG_REFRESH_MIN 0
22#define DRBD_DIALOG_REFRESH_MAX 600
23
24/* valid port number */
25#define DRBD_PORT_MIN 1
26#define DRBD_PORT_MAX 0xffff
27
28/* startup { */
29 /* if you want more than 3.4 days, disable */
30#define DRBD_WFC_TIMEOUT_MIN 0
31#define DRBD_WFC_TIMEOUT_MAX 300000
32#define DRBD_WFC_TIMEOUT_DEF 0
33
34#define DRBD_DEGR_WFC_TIMEOUT_MIN 0
35#define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
36#define DRBD_DEGR_WFC_TIMEOUT_DEF 0
37
38#define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
39#define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
40#define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
41/* }*/
42
43/* net { */
44 /* timeout, unit centi seconds
45 * more than one minute timeout is not usefull */
46#define DRBD_TIMEOUT_MIN 1
47#define DRBD_TIMEOUT_MAX 600
48#define DRBD_TIMEOUT_DEF 60 /* 6 seconds */
49
50 /* active connection retries when C_WF_CONNECTION */
51#define DRBD_CONNECT_INT_MIN 1
52#define DRBD_CONNECT_INT_MAX 120
53#define DRBD_CONNECT_INT_DEF 10 /* seconds */
54
55 /* keep-alive probes when idle */
56#define DRBD_PING_INT_MIN 1
57#define DRBD_PING_INT_MAX 120
58#define DRBD_PING_INT_DEF 10
59
60 /* timeout for the ping packets.*/
61#define DRBD_PING_TIMEO_MIN 1
62#define DRBD_PING_TIMEO_MAX 100
63#define DRBD_PING_TIMEO_DEF 5
64
65 /* max number of write requests between write barriers */
66#define DRBD_MAX_EPOCH_SIZE_MIN 1
67#define DRBD_MAX_EPOCH_SIZE_MAX 20000
68#define DRBD_MAX_EPOCH_SIZE_DEF 2048
69
70 /* I don't think that a tcp send buffer of more than 10M is usefull */
71#define DRBD_SNDBUF_SIZE_MIN 0
72#define DRBD_SNDBUF_SIZE_MAX (10<<20)
73#define DRBD_SNDBUF_SIZE_DEF 0
74
75#define DRBD_RCVBUF_SIZE_MIN 0
76#define DRBD_RCVBUF_SIZE_MAX (10<<20)
77#define DRBD_RCVBUF_SIZE_DEF 0
78
79 /* @4k PageSize -> 128kB - 512MB */
80#define DRBD_MAX_BUFFERS_MIN 32
81#define DRBD_MAX_BUFFERS_MAX 131072
82#define DRBD_MAX_BUFFERS_DEF 2048
83
84 /* @4k PageSize -> 4kB - 512MB */
85#define DRBD_UNPLUG_WATERMARK_MIN 1
86#define DRBD_UNPLUG_WATERMARK_MAX 131072
87#define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
88
89 /* 0 is disabled.
90 * 200 should be more than enough even for very short timeouts */
91#define DRBD_KO_COUNT_MIN 0
92#define DRBD_KO_COUNT_MAX 200
93#define DRBD_KO_COUNT_DEF 0
94/* } */
95
96/* syncer { */
97 /* FIXME allow rate to be zero? */
98#define DRBD_RATE_MIN 1
99/* channel bonding 10 GbE, or other hardware */
100#define DRBD_RATE_MAX (4 << 20)
101#define DRBD_RATE_DEF 250 /* kb/second */
102
103 /* less than 7 would hit performance unneccessarily.
104 * 3833 is the largest prime that still does fit
105 * into 64 sectors of activity log */
106#define DRBD_AL_EXTENTS_MIN 7
107#define DRBD_AL_EXTENTS_MAX 3833
108#define DRBD_AL_EXTENTS_DEF 127
109
110#define DRBD_AFTER_MIN -1
111#define DRBD_AFTER_MAX 255
112#define DRBD_AFTER_DEF -1
113
114/* } */
115
116/* drbdsetup XY resize -d Z
117 * you are free to reduce the device size to nothing, if you want to.
118 * the upper limit with 64bit kernel, enough ram and flexible meta data
119 * is 16 TB, currently. */
120/* DRBD_MAX_SECTORS */
121#define DRBD_DISK_SIZE_SECT_MIN 0
122#define DRBD_DISK_SIZE_SECT_MAX (16 * (2LLU << 30))
123#define DRBD_DISK_SIZE_SECT_DEF 0 /* = disabled = no user size... */
124
125#define DRBD_ON_IO_ERROR_DEF EP_PASS_ON
126#define DRBD_FENCING_DEF FP_DONT_CARE
127#define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
128#define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
129#define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
130#define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
131
132#define DRBD_MAX_BIO_BVECS_MIN 0
133#define DRBD_MAX_BIO_BVECS_MAX 128
134#define DRBD_MAX_BIO_BVECS_DEF 0
135
136#undef RANGE
137#endif