1 /* SPDX-License-Identifier: GPL-2.0-only */
4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
8 * Our current limitations.
9 * Some of them are hard limits,
10 * some of them are arbitrary range limits, that make it easier to provide
11 * feedback about nonsense settings for certain configurable values.
15 #define DRBD_LIMITS_H 1
17 #define DEBUG_RANGE_CHECK 0
19 #define DRBD_MINOR_COUNT_MIN 1
20 #define DRBD_MINOR_COUNT_MAX 255
21 #define DRBD_MINOR_COUNT_DEF 32
22 #define DRBD_MINOR_COUNT_SCALE '1'
24 #define DRBD_VOLUME_MAX 65535
26 #define DRBD_DIALOG_REFRESH_MIN 0
27 #define DRBD_DIALOG_REFRESH_MAX 600
28 #define DRBD_DIALOG_REFRESH_SCALE '1'
30 /* valid port number */
31 #define DRBD_PORT_MIN 1
32 #define DRBD_PORT_MAX 0xffff
33 #define DRBD_PORT_SCALE '1'
36 /* if you want more than 3.4 days, disable */
37 #define DRBD_WFC_TIMEOUT_MIN 0
38 #define DRBD_WFC_TIMEOUT_MAX 300000
39 #define DRBD_WFC_TIMEOUT_DEF 0
40 #define DRBD_WFC_TIMEOUT_SCALE '1'
42 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
43 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
44 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
45 #define DRBD_DEGR_WFC_TIMEOUT_SCALE '1'
47 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
48 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
49 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
50 #define DRBD_OUTDATED_WFC_TIMEOUT_SCALE '1'
54 /* timeout, unit centi seconds
55 * more than one minute timeout is not useful */
56 #define DRBD_TIMEOUT_MIN 1
57 #define DRBD_TIMEOUT_MAX 600
58 #define DRBD_TIMEOUT_DEF 60 /* 6 seconds */
59 #define DRBD_TIMEOUT_SCALE '1'
61 /* If backing disk takes longer than disk_timeout, mark the disk as failed */
62 #define DRBD_DISK_TIMEOUT_MIN 0 /* 0 = disabled */
63 #define DRBD_DISK_TIMEOUT_MAX 6000 /* 10 Minutes */
64 #define DRBD_DISK_TIMEOUT_DEF 0 /* disabled */
65 #define DRBD_DISK_TIMEOUT_SCALE '1'
67 /* active connection retries when C_WF_CONNECTION */
68 #define DRBD_CONNECT_INT_MIN 1
69 #define DRBD_CONNECT_INT_MAX 120
70 #define DRBD_CONNECT_INT_DEF 10 /* seconds */
71 #define DRBD_CONNECT_INT_SCALE '1'
73 /* keep-alive probes when idle */
74 #define DRBD_PING_INT_MIN 1
75 #define DRBD_PING_INT_MAX 120
76 #define DRBD_PING_INT_DEF 10
77 #define DRBD_PING_INT_SCALE '1'
79 /* timeout for the ping packets.*/
80 #define DRBD_PING_TIMEO_MIN 1
81 #define DRBD_PING_TIMEO_MAX 300
82 #define DRBD_PING_TIMEO_DEF 5
83 #define DRBD_PING_TIMEO_SCALE '1'
85 /* max number of write requests between write barriers */
86 #define DRBD_MAX_EPOCH_SIZE_MIN 1
87 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
88 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
89 #define DRBD_MAX_EPOCH_SIZE_SCALE '1'
91 /* I don't think that a tcp send buffer of more than 10M is useful */
92 #define DRBD_SNDBUF_SIZE_MIN 0
93 #define DRBD_SNDBUF_SIZE_MAX (10<<20)
94 #define DRBD_SNDBUF_SIZE_DEF 0
95 #define DRBD_SNDBUF_SIZE_SCALE '1'
97 #define DRBD_RCVBUF_SIZE_MIN 0
98 #define DRBD_RCVBUF_SIZE_MAX (10<<20)
99 #define DRBD_RCVBUF_SIZE_DEF 0
100 #define DRBD_RCVBUF_SIZE_SCALE '1'
102 /* @4k PageSize -> 128kB - 512MB */
103 #define DRBD_MAX_BUFFERS_MIN 32
104 #define DRBD_MAX_BUFFERS_MAX 131072
105 #define DRBD_MAX_BUFFERS_DEF 2048
106 #define DRBD_MAX_BUFFERS_SCALE '1'
108 /* @4k PageSize -> 4kB - 512MB */
109 #define DRBD_UNPLUG_WATERMARK_MIN 1
110 #define DRBD_UNPLUG_WATERMARK_MAX 131072
111 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
112 #define DRBD_UNPLUG_WATERMARK_SCALE '1'
115 * 200 should be more than enough even for very short timeouts */
116 #define DRBD_KO_COUNT_MIN 0
117 #define DRBD_KO_COUNT_MAX 200
118 #define DRBD_KO_COUNT_DEF 7
119 #define DRBD_KO_COUNT_SCALE '1'
123 /* FIXME allow rate to be zero? */
124 #define DRBD_RESYNC_RATE_MIN 1
125 /* channel bonding 10 GbE, or other hardware */
126 #define DRBD_RESYNC_RATE_MAX (4 << 20)
127 #define DRBD_RESYNC_RATE_DEF 250
128 #define DRBD_RESYNC_RATE_SCALE 'k' /* kilobytes */
130 #define DRBD_AL_EXTENTS_MIN 67
131 /* we use u16 as "slot number", (u16)~0 is "FREE".
132 * If you use >= 292 kB on-disk ring buffer,
133 * this is the maximum you can use: */
134 #define DRBD_AL_EXTENTS_MAX 0xfffe
135 #define DRBD_AL_EXTENTS_DEF 1237
136 #define DRBD_AL_EXTENTS_SCALE '1'
138 #define DRBD_MINOR_NUMBER_MIN -1
139 #define DRBD_MINOR_NUMBER_MAX ((1 << 20) - 1)
140 #define DRBD_MINOR_NUMBER_DEF -1
141 #define DRBD_MINOR_NUMBER_SCALE '1'
145 /* drbdsetup XY resize -d Z
146 * you are free to reduce the device size to nothing, if you want to.
147 * the upper limit with 64bit kernel, enough ram and flexible meta data
148 * is 1 PiB, currently. */
149 /* DRBD_MAX_SECTORS */
150 #define DRBD_DISK_SIZE_MIN 0
151 #define DRBD_DISK_SIZE_MAX (1 * (2LLU << 40))
152 #define DRBD_DISK_SIZE_DEF 0 /* = disabled = no user size... */
153 #define DRBD_DISK_SIZE_SCALE 's' /* sectors */
155 #define DRBD_ON_IO_ERROR_DEF EP_DETACH
156 #define DRBD_FENCING_DEF FP_DONT_CARE
157 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
158 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
159 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
160 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
161 #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
162 #define DRBD_ON_CONGESTION_DEF OC_BLOCK
163 #define DRBD_READ_BALANCING_DEF RB_PREFER_LOCAL
165 #define DRBD_MAX_BIO_BVECS_MIN 0
166 #define DRBD_MAX_BIO_BVECS_MAX 128
167 #define DRBD_MAX_BIO_BVECS_DEF 0
168 #define DRBD_MAX_BIO_BVECS_SCALE '1'
170 #define DRBD_C_PLAN_AHEAD_MIN 0
171 #define DRBD_C_PLAN_AHEAD_MAX 300
172 #define DRBD_C_PLAN_AHEAD_DEF 20
173 #define DRBD_C_PLAN_AHEAD_SCALE '1'
175 #define DRBD_C_DELAY_TARGET_MIN 1
176 #define DRBD_C_DELAY_TARGET_MAX 100
177 #define DRBD_C_DELAY_TARGET_DEF 10
178 #define DRBD_C_DELAY_TARGET_SCALE '1'
180 #define DRBD_C_FILL_TARGET_MIN 0
181 #define DRBD_C_FILL_TARGET_MAX (1<<20) /* 500MByte in sec */
182 #define DRBD_C_FILL_TARGET_DEF 100 /* Try to place 50KiB in socket send buffer during resync */
183 #define DRBD_C_FILL_TARGET_SCALE 's' /* sectors */
185 #define DRBD_C_MAX_RATE_MIN 250
186 #define DRBD_C_MAX_RATE_MAX (4 << 20)
187 #define DRBD_C_MAX_RATE_DEF 102400
188 #define DRBD_C_MAX_RATE_SCALE 'k' /* kilobytes */
190 #define DRBD_C_MIN_RATE_MIN 0
191 #define DRBD_C_MIN_RATE_MAX (4 << 20)
192 #define DRBD_C_MIN_RATE_DEF 250
193 #define DRBD_C_MIN_RATE_SCALE 'k' /* kilobytes */
195 #define DRBD_CONG_FILL_MIN 0
196 #define DRBD_CONG_FILL_MAX (10<<21) /* 10GByte in sectors */
197 #define DRBD_CONG_FILL_DEF 0
198 #define DRBD_CONG_FILL_SCALE 's' /* sectors */
200 #define DRBD_CONG_EXTENTS_MIN DRBD_AL_EXTENTS_MIN
201 #define DRBD_CONG_EXTENTS_MAX DRBD_AL_EXTENTS_MAX
202 #define DRBD_CONG_EXTENTS_DEF DRBD_AL_EXTENTS_DEF
203 #define DRBD_CONG_EXTENTS_SCALE DRBD_AL_EXTENTS_SCALE
205 #define DRBD_PROTOCOL_DEF DRBD_PROT_C
207 #define DRBD_DISK_BARRIER_DEF 0
208 #define DRBD_DISK_FLUSHES_DEF 1
209 #define DRBD_DISK_DRAIN_DEF 1
210 #define DRBD_MD_FLUSHES_DEF 1
211 #define DRBD_TCP_CORK_DEF 1
212 #define DRBD_AL_UPDATES_DEF 1
214 /* We used to ignore the discard_zeroes_data setting.
215 * To not change established (and expected) behaviour,
216 * by default assume that, for discard_zeroes_data=0,
217 * we can make that an effective discard_zeroes_data=1,
218 * if we only explicitly zero-out unaligned partial chunks. */
219 #define DRBD_DISCARD_ZEROES_IF_ALIGNED_DEF 1
221 /* Some backends pretend to support WRITE SAME,
222 * but fail such requests when they are actually submitted.
223 * This is to tell DRBD to not even try. */
224 #define DRBD_DISABLE_WRITE_SAME_DEF 0
226 #define DRBD_ALLOW_TWO_PRIMARIES_DEF 0
227 #define DRBD_ALWAYS_ASBP_DEF 0
228 #define DRBD_USE_RLE_DEF 1
229 #define DRBD_CSUMS_AFTER_CRASH_ONLY_DEF 0
231 #define DRBD_AL_STRIPES_MIN 1
232 #define DRBD_AL_STRIPES_MAX 1024
233 #define DRBD_AL_STRIPES_DEF 1
234 #define DRBD_AL_STRIPES_SCALE '1'
236 #define DRBD_AL_STRIPE_SIZE_MIN 4
237 #define DRBD_AL_STRIPE_SIZE_MAX 16777216
238 #define DRBD_AL_STRIPE_SIZE_DEF 32
239 #define DRBD_AL_STRIPE_SIZE_SCALE 'k' /* kilobytes */
241 #define DRBD_SOCKET_CHECK_TIMEO_MIN 0
242 #define DRBD_SOCKET_CHECK_TIMEO_MAX DRBD_PING_TIMEO_MAX
243 #define DRBD_SOCKET_CHECK_TIMEO_DEF 0
244 #define DRBD_SOCKET_CHECK_TIMEO_SCALE '1'
246 #define DRBD_RS_DISCARD_GRANULARITY_MIN 0
247 #define DRBD_RS_DISCARD_GRANULARITY_MAX (1<<20) /* 1MiByte */
248 #define DRBD_RS_DISCARD_GRANULARITY_DEF 0 /* disabled by default */
249 #define DRBD_RS_DISCARD_GRANULARITY_SCALE '1' /* bytes */