1/* SPDX-License-Identifier: GPL-2.0-only */ 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 1U 20#define DRBD_MINOR_COUNT_MAX 255U 21#define DRBD_MINOR_COUNT_DEF 32U 22#define DRBD_MINOR_COUNT_SCALE '1' 23 24#define DRBD_VOLUME_MAX 65534U 25 26#define DRBD_DIALOG_REFRESH_MIN 0U 27#define DRBD_DIALOG_REFRESH_MAX 600U 28#define DRBD_DIALOG_REFRESH_SCALE '1' 29 30/* valid port number */ 31#define DRBD_PORT_MIN 1U 32#define DRBD_PORT_MAX 0xffffU 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 0U 38#define DRBD_WFC_TIMEOUT_MAX 300000U 39#define DRBD_WFC_TIMEOUT_DEF 0U 40#define DRBD_WFC_TIMEOUT_SCALE '1' 41 42#define DRBD_DEGR_WFC_TIMEOUT_MIN 0U 43#define DRBD_DEGR_WFC_TIMEOUT_MAX 300000U 44#define DRBD_DEGR_WFC_TIMEOUT_DEF 0U 45#define DRBD_DEGR_WFC_TIMEOUT_SCALE '1' 46 47#define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0U 48#define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000U 49#define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0U 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 1U 57#define DRBD_TIMEOUT_MAX 600U 58#define DRBD_TIMEOUT_DEF 60U /* 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 0U /* 0 = disabled */ 63#define DRBD_DISK_TIMEOUT_MAX 6000U /* 10 Minutes */ 64#define DRBD_DISK_TIMEOUT_DEF 0U /* disabled */ 65#define DRBD_DISK_TIMEOUT_SCALE '1' 66 67 /* active connection retries when C_WF_CONNECTION */ 68#define DRBD_CONNECT_INT_MIN 1U 69#define DRBD_CONNECT_INT_MAX 120U 70#define DRBD_CONNECT_INT_DEF 10U /* seconds */ 71#define DRBD_CONNECT_INT_SCALE '1' 72 73 /* keep-alive probes when idle */ 74#define DRBD_PING_INT_MIN 1U 75#define DRBD_PING_INT_MAX 120U 76#define DRBD_PING_INT_DEF 10U 77#define DRBD_PING_INT_SCALE '1' 78 79 /* timeout for the ping packets.*/ 80#define DRBD_PING_TIMEO_MIN 1U 81#define DRBD_PING_TIMEO_MAX 300U 82#define DRBD_PING_TIMEO_DEF 5U 83#define DRBD_PING_TIMEO_SCALE '1' 84 85 /* max number of write requests between write barriers */ 86#define DRBD_MAX_EPOCH_SIZE_MIN 1U 87#define DRBD_MAX_EPOCH_SIZE_MAX 20000U 88#define DRBD_MAX_EPOCH_SIZE_DEF 2048U 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 0U 93#define DRBD_SNDBUF_SIZE_MAX (10U<<20) 94#define DRBD_SNDBUF_SIZE_DEF 0U 95#define DRBD_SNDBUF_SIZE_SCALE '1' 96 97#define DRBD_RCVBUF_SIZE_MIN 0U 98#define DRBD_RCVBUF_SIZE_MAX (10U<<20) 99#define DRBD_RCVBUF_SIZE_DEF 0U 100#define DRBD_RCVBUF_SIZE_SCALE '1' 101 102 /* @4k PageSize -> 128kB - 512MB */ 103#define DRBD_MAX_BUFFERS_MIN 32U 104#define DRBD_MAX_BUFFERS_MAX 131072U 105#define DRBD_MAX_BUFFERS_DEF 2048U 106#define DRBD_MAX_BUFFERS_SCALE '1' 107 108 /* @4k PageSize -> 4kB - 512MB */ 109#define DRBD_UNPLUG_WATERMARK_MIN 1U 110#define DRBD_UNPLUG_WATERMARK_MAX 131072U 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 0U 117#define DRBD_KO_COUNT_MAX 200U 118#define DRBD_KO_COUNT_DEF 7U 119#define DRBD_KO_COUNT_SCALE '1' 120/* } */ 121 122/* syncer { */ 123 /* FIXME allow rate to be zero? */ 124#define DRBD_RESYNC_RATE_MIN 1U 125/* channel bonding 10 GbE, or other hardware */ 126#define DRBD_RESYNC_RATE_MAX (4 << 20) 127#define DRBD_RESYNC_RATE_DEF 250U 128#define DRBD_RESYNC_RATE_SCALE 'k' /* kilobytes */ 129 130#define DRBD_AL_EXTENTS_MIN 67U 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 0xfffeU 135#define DRBD_AL_EXTENTS_DEF 1237U 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 0LLU 151#define DRBD_DISK_SIZE_MAX (1LLU * (2LLU << 40)) 152#define DRBD_DISK_SIZE_DEF 0LLU /* = 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 0U 166#define DRBD_MAX_BIO_BVECS_MAX 128U 167#define DRBD_MAX_BIO_BVECS_DEF 0U 168#define DRBD_MAX_BIO_BVECS_SCALE '1' 169 170#define DRBD_C_PLAN_AHEAD_MIN 0U 171#define DRBD_C_PLAN_AHEAD_MAX 300U 172#define DRBD_C_PLAN_AHEAD_DEF 20U 173#define DRBD_C_PLAN_AHEAD_SCALE '1' 174 175#define DRBD_C_DELAY_TARGET_MIN 1U 176#define DRBD_C_DELAY_TARGET_MAX 100U 177#define DRBD_C_DELAY_TARGET_DEF 10U 178#define DRBD_C_DELAY_TARGET_SCALE '1' 179 180#define DRBD_C_FILL_TARGET_MIN 0U 181#define DRBD_C_FILL_TARGET_MAX (1U<<20) /* 500MByte in sec */ 182#define DRBD_C_FILL_TARGET_DEF 100U /* 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 250U 186#define DRBD_C_MAX_RATE_MAX (4U << 20) 187#define DRBD_C_MAX_RATE_DEF 102400U 188#define DRBD_C_MAX_RATE_SCALE 'k' /* kilobytes */ 189 190#define DRBD_C_MIN_RATE_MIN 0U 191#define DRBD_C_MIN_RATE_MAX (4U << 20) 192#define DRBD_C_MIN_RATE_DEF 250U 193#define DRBD_C_MIN_RATE_SCALE 'k' /* kilobytes */ 194 195#define DRBD_CONG_FILL_MIN 0U 196#define DRBD_CONG_FILL_MAX (10U<<21) /* 10GByte in sectors */ 197#define DRBD_CONG_FILL_DEF 0U 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 0U 208#define DRBD_DISK_FLUSHES_DEF 1U 209#define DRBD_DISK_DRAIN_DEF 1U 210#define DRBD_MD_FLUSHES_DEF 1U 211#define DRBD_TCP_CORK_DEF 1U 212#define DRBD_AL_UPDATES_DEF 1U 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 1U 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 0U 225 226#define DRBD_ALLOW_TWO_PRIMARIES_DEF 0U 227#define DRBD_ALWAYS_ASBP_DEF 0U 228#define DRBD_USE_RLE_DEF 1U 229#define DRBD_CSUMS_AFTER_CRASH_ONLY_DEF 0U 230 231#define DRBD_AL_STRIPES_MIN 1U 232#define DRBD_AL_STRIPES_MAX 1024U 233#define DRBD_AL_STRIPES_DEF 1U 234#define DRBD_AL_STRIPES_SCALE '1' 235 236#define DRBD_AL_STRIPE_SIZE_MIN 4U 237#define DRBD_AL_STRIPE_SIZE_MAX 16777216U 238#define DRBD_AL_STRIPE_SIZE_DEF 32U 239#define DRBD_AL_STRIPE_SIZE_SCALE 'k' /* kilobytes */ 240 241#define DRBD_SOCKET_CHECK_TIMEO_MIN 0U 242#define DRBD_SOCKET_CHECK_TIMEO_MAX DRBD_PING_TIMEO_MAX 243#define DRBD_SOCKET_CHECK_TIMEO_DEF 0U 244#define DRBD_SOCKET_CHECK_TIMEO_SCALE '1' 245 246#define DRBD_RS_DISCARD_GRANULARITY_MIN 0U 247#define DRBD_RS_DISCARD_GRANULARITY_MAX (1U<<20) /* 1MiByte */ 248#define DRBD_RS_DISCARD_GRANULARITY_DEF 0U /* disabled by default */ 249#define DRBD_RS_DISCARD_GRANULARITY_SCALE '1' /* bytes */ 250 251#endif 252