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