include/linux/drbd_limits.h

   1 /*
   2   drbd_limits.h
   3   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   4 */
   5
   6 /*
   7  * Our current limitations.
   8  * Some of them are hard limits,
   9  * some of them are arbitrary range limits, that make it easier to provide
  10  * feedback about nonsense settings for certain configurable values.
  11  */
  12
  13 #ifndef DRBD_LIMITS_H
  14 #define DRBD_LIMITS_H 1
  15
  16 #define DEBUG_RANGE_CHECK 0
  17
  18 #define DRBD_MINOR_COUNT_MIN 1
  19 #define DRBD_MINOR_COUNT_MAX 255
  20 #define DRBD_MINOR_COUNT_DEF 32
  21 #define DRBD_MINOR_COUNT_SCALE '1'
  22
  23 #define DRBD_VOLUME_MAX 65535
  24
  25 #define DRBD_DIALOG_REFRESH_MIN 0
  26 #define DRBD_DIALOG_REFRESH_MAX 600
  27 #define DRBD_DIALOG_REFRESH_SCALE '1'
  28
  29 /* valid port number */
  30 #define DRBD_PORT_MIN 1
  31 #define DRBD_PORT_MAX 0xffff
  32 #define DRBD_PORT_SCALE '1'
  33
  34 /* startup { */
  35   /* if you want more than 3.4 days, disable */
  36 #define DRBD_WFC_TIMEOUT_MIN 0
  37 #define DRBD_WFC_TIMEOUT_MAX 300000
  38 #define DRBD_WFC_TIMEOUT_DEF 0
  39 #define DRBD_WFC_TIMEOUT_SCALE '1'
  40
  41 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
  42 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
  43 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
  44 #define DRBD_DEGR_WFC_TIMEOUT_SCALE '1'
  45
  46 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
  47 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
  48 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
  49 #define DRBD_OUTDATED_WFC_TIMEOUT_SCALE '1'
  50 /* }*/
  51
  52 /* net { */
  53   /* timeout, unit centi seconds
  54    * more than one minute timeout is not useful */
  55 #define DRBD_TIMEOUT_MIN 1
  56 #define DRBD_TIMEOUT_MAX 600
  57 #define DRBD_TIMEOUT_DEF 60       /* 6 seconds */
  58 #define DRBD_TIMEOUT_SCALE '1'
  59
  60  /* If backing disk takes longer than disk_timeout, mark the disk as failed */
  61 #define DRBD_DISK_TIMEOUT_MIN 0    /* 0 = disabled */
  62 #define DRBD_DISK_TIMEOUT_MAX 6000 /* 10 Minutes */
  63 #define DRBD_DISK_TIMEOUT_DEF 0    /* disabled */
  64 #define DRBD_DISK_TIMEOUT_SCALE '1'
  65
  66   /* active connection retries when C_WF_CONNECTION */
  67 #define DRBD_CONNECT_INT_MIN 1
  68 #define DRBD_CONNECT_INT_MAX 120
  69 #define DRBD_CONNECT_INT_DEF 10   /* seconds */
  70 #define DRBD_CONNECT_INT_SCALE '1'
  71
  72   /* keep-alive probes when idle */
  73 #define DRBD_PING_INT_MIN 1
  74 #define DRBD_PING_INT_MAX 120
  75 #define DRBD_PING_INT_DEF 10
  76 #define DRBD_PING_INT_SCALE '1'
  77
  78  /* timeout for the ping packets.*/
  79 #define DRBD_PING_TIMEO_MIN  1
  80 #define DRBD_PING_TIMEO_MAX  300
  81 #define DRBD_PING_TIMEO_DEF  5
  82 #define DRBD_PING_TIMEO_SCALE '1'
  83
  84   /* max number of write requests between write barriers */
  85 #define DRBD_MAX_EPOCH_SIZE_MIN 1
  86 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
  87 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
  88 #define DRBD_MAX_EPOCH_SIZE_SCALE '1'
  89
  90   /* I don't think that a tcp send buffer of more than 10M is useful */
  91 #define DRBD_SNDBUF_SIZE_MIN  0
  92 #define DRBD_SNDBUF_SIZE_MAX  (10<<20)
  93 #define DRBD_SNDBUF_SIZE_DEF  0
  94 #define DRBD_SNDBUF_SIZE_SCALE '1'
  95
  96 #define DRBD_RCVBUF_SIZE_MIN  0
  97 #define DRBD_RCVBUF_SIZE_MAX  (10<<20)
  98 #define DRBD_RCVBUF_SIZE_DEF  0
  99 #define DRBD_RCVBUF_SIZE_SCALE '1'
 100
 101   /* @4k PageSize -> 128kB - 512MB */
 102 #define DRBD_MAX_BUFFERS_MIN  32
 103 #define DRBD_MAX_BUFFERS_MAX  131072
 104 #define DRBD_MAX_BUFFERS_DEF  2048
 105 #define DRBD_MAX_BUFFERS_SCALE '1'
 106
 107   /* @4k PageSize -> 4kB - 512MB */
 108 #define DRBD_UNPLUG_WATERMARK_MIN  1
 109 #define DRBD_UNPLUG_WATERMARK_MAX  131072
 110 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
 111 #define DRBD_UNPLUG_WATERMARK_SCALE '1'
 112
 113   /* 0 is disabled.
 114    * 200 should be more than enough even for very short timeouts */
 115 #define DRBD_KO_COUNT_MIN  0
 116 #define DRBD_KO_COUNT_MAX  200
 117 #define DRBD_KO_COUNT_DEF  7
 118 #define DRBD_KO_COUNT_SCALE '1'
 119 /* } */
 120
 121 /* syncer { */
 122   /* FIXME allow rate to be zero? */
 123 #define DRBD_RESYNC_RATE_MIN 1
 124 /* channel bonding 10 GbE, or other hardware */
 125 #define DRBD_RESYNC_RATE_MAX (4 << 20)
 126 #define DRBD_RESYNC_RATE_DEF 250
 127 #define DRBD_RESYNC_RATE_SCALE 'k'  /* kilobytes */
 128
 129   /* less than 7 would hit performance unnecessarily.
 130    * 919 slots context information per transaction,
 131    * 32k activity log, 4k transaction size,
 132    * one transaction in flight:
 133    * 919 * 7 = 6433 */
 134 #define DRBD_AL_EXTENTS_MIN  7
 135 #define DRBD_AL_EXTENTS_MAX  6433
 136 #define DRBD_AL_EXTENTS_DEF  1237
 137 #define DRBD_AL_EXTENTS_SCALE '1'
 138
 139 #define DRBD_MINOR_NUMBER_MIN  -1
 140 #define DRBD_MINOR_NUMBER_MAX  ((1 << 20) - 1)
 141 #define DRBD_MINOR_NUMBER_DEF  -1
 142 #define DRBD_MINOR_NUMBER_SCALE '1'
 143
 144 /* } */
 145
 146 /* drbdsetup XY resize -d Z
 147  * you are free to reduce the device size to nothing, if you want to.
 148  * the upper limit with 64bit kernel, enough ram and flexible meta data
 149  * is 1 PiB, currently. */
 150 /* DRBD_MAX_SECTORS */
 151 #define DRBD_DISK_SIZE_MIN  0
 152 #define DRBD_DISK_SIZE_MAX  (1 * (2LLU << 40))
 153 #define DRBD_DISK_SIZE_DEF  0 /* = disabled = no user size... */
 154 #define DRBD_DISK_SIZE_SCALE 's'  /* sectors */
 155
 156 #define DRBD_ON_IO_ERROR_DEF EP_DETACH
 157 #define DRBD_FENCING_DEF FP_DONT_CARE
 158 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
 159 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
 160 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
 161 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
 162 #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
 163 #define DRBD_ON_CONGESTION_DEF OC_BLOCK
 164 #define DRBD_READ_BALANCING_DEF RB_PREFER_LOCAL
 165
 166 #define DRBD_MAX_BIO_BVECS_MIN 0
 167 #define DRBD_MAX_BIO_BVECS_MAX 128
 168 #define DRBD_MAX_BIO_BVECS_DEF 0
 169 #define DRBD_MAX_BIO_BVECS_SCALE '1'
 170
 171 #define DRBD_C_PLAN_AHEAD_MIN  0
 172 #define DRBD_C_PLAN_AHEAD_MAX  300
 173 #define DRBD_C_PLAN_AHEAD_DEF  20
 174 #define DRBD_C_PLAN_AHEAD_SCALE '1'
 175
 176 #define DRBD_C_DELAY_TARGET_MIN 1
 177 #define DRBD_C_DELAY_TARGET_MAX 100
 178 #define DRBD_C_DELAY_TARGET_DEF 10
 179 #define DRBD_C_DELAY_TARGET_SCALE '1'
 180
 181 #define DRBD_C_FILL_TARGET_MIN 0
 182 #define DRBD_C_FILL_TARGET_MAX (1<<20) /* 500MByte in sec */
 183 #define DRBD_C_FILL_TARGET_DEF 100 /* Try to place 50KiB in socket send buffer during resync */
 184 #define DRBD_C_FILL_TARGET_SCALE 's'  /* sectors */
 185
 186 #define DRBD_C_MAX_RATE_MIN     250
 187 #define DRBD_C_MAX_RATE_MAX     (4 << 20)
 188 #define DRBD_C_MAX_RATE_DEF     102400
 189 #define DRBD_C_MAX_RATE_SCALE   'k'  /* kilobytes */
 190
 191 #define DRBD_C_MIN_RATE_MIN     0
 192 #define DRBD_C_MIN_RATE_MAX     (4 << 20)
 193 #define DRBD_C_MIN_RATE_DEF     250
 194 #define DRBD_C_MIN_RATE_SCALE   'k'  /* kilobytes */
 195
 196 #define DRBD_CONG_FILL_MIN      0
 197 #define DRBD_CONG_FILL_MAX      (10<<21) /* 10GByte in sectors */
 198 #define DRBD_CONG_FILL_DEF      0
 199 #define DRBD_CONG_FILL_SCALE    's'  /* sectors */
 200
 201 #define DRBD_CONG_EXTENTS_MIN   DRBD_AL_EXTENTS_MIN
 202 #define DRBD_CONG_EXTENTS_MAX   DRBD_AL_EXTENTS_MAX
 203 #define DRBD_CONG_EXTENTS_DEF   DRBD_AL_EXTENTS_DEF
 204 #define DRBD_CONG_EXTENTS_SCALE DRBD_AL_EXTENTS_SCALE
 205
 206 #define DRBD_PROTOCOL_DEF DRBD_PROT_C
 207
 208 #define DRBD_DISK_BARRIER_DEF   0
 209 #define DRBD_DISK_FLUSHES_DEF   1
 210 #define DRBD_DISK_DRAIN_DEF     1
 211 #define DRBD_MD_FLUSHES_DEF     1
 212 #define DRBD_TCP_CORK_DEF       1
 213 #define DRBD_AL_UPDATES_DEF     1
 214
 215 #define DRBD_ALLOW_TWO_PRIMARIES_DEF    0
 216 #define DRBD_ALWAYS_ASBP_DEF    0
 217 #define DRBD_USE_RLE_DEF        1
 218
 219 #endif