include/linux/drbd

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   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
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root/include/linux/drbd_limits.h

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