1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 drbd_limits.h
4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
5*/
6
7/*
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.
12 */
13
14#ifndef DRBD_LIMITS_H
15#define DRBD_LIMITS_H 1
16
17#define DEBUG_RANGE_CHECK 0
18
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'
23
24#define DRBD_VOLUME_MAX 65535
25
26#define DRBD_DIALOG_REFRESH_MIN 0
27#define DRBD_DIALOG_REFRESH_MAX 600
28#define DRBD_DIALOG_REFRESH_SCALE '1'
29
30/* valid port number */
31#define DRBD_PORT_MIN 1
32#define DRBD_PORT_MAX 0xffff
33#define DRBD_PORT_SCALE '1'
34
35/* startup { */
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'
41
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'
46
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'
51/* }*/
52
53/* net { */
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'
60
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'
66
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'
72
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'
78
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'
84
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'
90
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'
96
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'
101
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'
107
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'
113
114 /* 0 is disabled.
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'
120/* } */
121
122/* syncer { */
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 */
129
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'
137
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'
142
143/* } */
144
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 */
154
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
164
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'
169
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'
174
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'
179
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 */
184
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 */
189
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 */
194
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 */
199
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
204
205#define DRBD_PROTOCOL_DEF DRBD_PROT_C
206
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
213
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
220
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
225
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
230
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'
235
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 */
240
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'
245
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 */
250
251#endif
252