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 256
20 #define DRBD_MINOR_COUNT_DEF 32
21 
22 #define DRBD_DIALOG_REFRESH_MIN 0
23 #define DRBD_DIALOG_REFRESH_MAX 600
24 
25 /* valid port number */
26 #define DRBD_PORT_MIN 1
27 #define DRBD_PORT_MAX 0xffff
28 
29 /* startup { */
30   /* if you want more than 3.4 days, disable */
31 #define DRBD_WFC_TIMEOUT_MIN 0
32 #define DRBD_WFC_TIMEOUT_MAX 300000
33 #define DRBD_WFC_TIMEOUT_DEF 0
34 
35 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
36 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
37 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
38 
39 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
40 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
41 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
42 /* }*/
43 
44 /* net { */
45   /* timeout, unit centi seconds
46    * more than one minute timeout is not useful */
47 #define DRBD_TIMEOUT_MIN 1
48 #define DRBD_TIMEOUT_MAX 600
49 #define DRBD_TIMEOUT_DEF 60       /* 6 seconds */
50 
51   /* active connection retries when C_WF_CONNECTION */
52 #define DRBD_CONNECT_INT_MIN 1
53 #define DRBD_CONNECT_INT_MAX 120
54 #define DRBD_CONNECT_INT_DEF 10   /* seconds */
55 
56   /* keep-alive probes when idle */
57 #define DRBD_PING_INT_MIN 1
58 #define DRBD_PING_INT_MAX 120
59 #define DRBD_PING_INT_DEF 10
60 
61  /* timeout for the ping packets.*/
62 #define DRBD_PING_TIMEO_MIN  1
63 #define DRBD_PING_TIMEO_MAX  100
64 #define DRBD_PING_TIMEO_DEF  5
65 
66   /* max number of write requests between write barriers */
67 #define DRBD_MAX_EPOCH_SIZE_MIN 1
68 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
69 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
70 
71   /* I don't think that a tcp send buffer of more than 10M is useful */
72 #define DRBD_SNDBUF_SIZE_MIN  0
73 #define DRBD_SNDBUF_SIZE_MAX  (10<<20)
74 #define DRBD_SNDBUF_SIZE_DEF  0
75 
76 #define DRBD_RCVBUF_SIZE_MIN  0
77 #define DRBD_RCVBUF_SIZE_MAX  (10<<20)
78 #define DRBD_RCVBUF_SIZE_DEF  0
79 
80   /* @4k PageSize -> 128kB - 512MB */
81 #define DRBD_MAX_BUFFERS_MIN  32
82 #define DRBD_MAX_BUFFERS_MAX  131072
83 #define DRBD_MAX_BUFFERS_DEF  2048
84 
85   /* @4k PageSize -> 4kB - 512MB */
86 #define DRBD_UNPLUG_WATERMARK_MIN  1
87 #define DRBD_UNPLUG_WATERMARK_MAX  131072
88 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
89 
90   /* 0 is disabled.
91    * 200 should be more than enough even for very short timeouts */
92 #define DRBD_KO_COUNT_MIN  0
93 #define DRBD_KO_COUNT_MAX  200
94 #define DRBD_KO_COUNT_DEF  0
95 /* } */
96 
97 /* syncer { */
98   /* FIXME allow rate to be zero? */
99 #define DRBD_RATE_MIN 1
100 /* channel bonding 10 GbE, or other hardware */
101 #define DRBD_RATE_MAX (4 << 20)
102 #define DRBD_RATE_DEF 250  /* kb/second */
103 
104   /* less than 7 would hit performance unnecessarily.
105    * 3833 is the largest prime that still does fit
106    * into 64 sectors of activity log */
107 #define DRBD_AL_EXTENTS_MIN  7
108 #define DRBD_AL_EXTENTS_MAX  3833
109 #define DRBD_AL_EXTENTS_DEF  127
110 
111 #define DRBD_AFTER_MIN  -1
112 #define DRBD_AFTER_MAX  255
113 #define DRBD_AFTER_DEF  -1
114 
115 /* } */
116 
117 /* drbdsetup XY resize -d Z
118  * you are free to reduce the device size to nothing, if you want to.
119  * the upper limit with 64bit kernel, enough ram and flexible meta data
120  * is 1 PiB, currently. */
121 /* DRBD_MAX_SECTORS */
122 #define DRBD_DISK_SIZE_SECT_MIN  0
123 #define DRBD_DISK_SIZE_SECT_MAX  (1 * (2LLU << 40))
124 #define DRBD_DISK_SIZE_SECT_DEF  0 /* = disabled = no user size... */
125 
126 #define DRBD_ON_IO_ERROR_DEF EP_PASS_ON
127 #define DRBD_FENCING_DEF FP_DONT_CARE
128 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
129 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
130 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
131 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
132 #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
133 #define DRBD_ON_CONGESTION_DEF OC_BLOCK
134 
135 #define DRBD_MAX_BIO_BVECS_MIN 0
136 #define DRBD_MAX_BIO_BVECS_MAX 128
137 #define DRBD_MAX_BIO_BVECS_DEF 0
138 
139 #define DRBD_C_PLAN_AHEAD_MIN  0
140 #define DRBD_C_PLAN_AHEAD_MAX  300
141 #define DRBD_C_PLAN_AHEAD_DEF  0 /* RS rate controller disabled by default */
142 
143 #define DRBD_C_DELAY_TARGET_MIN 1
144 #define DRBD_C_DELAY_TARGET_MAX 100
145 #define DRBD_C_DELAY_TARGET_DEF 10
146 
147 #define DRBD_C_FILL_TARGET_MIN 0
148 #define DRBD_C_FILL_TARGET_MAX (1<<20) /* 500MByte in sec */
149 #define DRBD_C_FILL_TARGET_DEF 0 /* By default disabled -> controlled by delay_target */
150 
151 #define DRBD_C_MAX_RATE_MIN     250 /* kByte/sec */
152 #define DRBD_C_MAX_RATE_MAX     (4 << 20)
153 #define DRBD_C_MAX_RATE_DEF     102400
154 
155 #define DRBD_C_MIN_RATE_MIN     0 /* kByte/sec */
156 #define DRBD_C_MIN_RATE_MAX     (4 << 20)
157 #define DRBD_C_MIN_RATE_DEF     4096
158 
159 #define DRBD_CONG_FILL_MIN	0
160 #define DRBD_CONG_FILL_MAX	(10<<21) /* 10GByte in sectors */
161 #define DRBD_CONG_FILL_DEF	0
162 
163 #define DRBD_CONG_EXTENTS_MIN	DRBD_AL_EXTENTS_MIN
164 #define DRBD_CONG_EXTENTS_MAX	DRBD_AL_EXTENTS_MAX
165 #define DRBD_CONG_EXTENTS_DEF	DRBD_AL_EXTENTS_DEF
166 
167 #undef RANGE
168 #endif
169