/*
    drbd_limits.h
    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
  */
  
  /*
   * Our current limitations.
   * Some of them are hard limits,
   * some of them are arbitrary range limits, that make it easier to provide
   * feedback about nonsense settings for certain configurable values.
   */
  
  #ifndef DRBD_LIMITS_H
  #define DRBD_LIMITS_H 1
  
  #define DEBUG_RANGE_CHECK 0
  
  #define DRBD_MINOR_COUNT_MIN 1
  #define DRBD_MINOR_COUNT_MAX 255
  #define DRBD_MINOR_COUNT_DEF 32
  #define DRBD_MINOR_COUNT_SCALE '1'
  
  #define DRBD_VOLUME_MAX 65535
  
  #define DRBD_DIALOG_REFRESH_MIN 0
  #define DRBD_DIALOG_REFRESH_MAX 600
  #define DRBD_DIALOG_REFRESH_SCALE '1'
  
  /* valid port number */
  #define DRBD_PORT_MIN 1
  #define DRBD_PORT_MAX 0xffff
  #define DRBD_PORT_SCALE '1'
  
  /* startup { */
    /* if you want more than 3.4 days, disable */
  #define DRBD_WFC_TIMEOUT_MIN 0
  #define DRBD_WFC_TIMEOUT_MAX 300000
  #define DRBD_WFC_TIMEOUT_DEF 0
  #define DRBD_WFC_TIMEOUT_SCALE '1'
  
  #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
  #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
  #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
  #define DRBD_DEGR_WFC_TIMEOUT_SCALE '1'
  
  #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
  #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
  #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
  #define DRBD_OUTDATED_WFC_TIMEOUT_SCALE '1'
  /* }*/
  
  /* net { */
    /* timeout, unit centi seconds
     * more than one minute timeout is not useful */
  #define DRBD_TIMEOUT_MIN 1
  #define DRBD_TIMEOUT_MAX 600
  #define DRBD_TIMEOUT_DEF 60       /* 6 seconds */
  #define DRBD_TIMEOUT_SCALE '1'
  
   /* If backing disk takes longer than disk_timeout, mark the disk as failed */
  #define DRBD_DISK_TIMEOUT_MIN 0    /* 0 = disabled */
  #define DRBD_DISK_TIMEOUT_MAX 6000 /* 10 Minutes */
  #define DRBD_DISK_TIMEOUT_DEF 0    /* disabled */
  #define DRBD_DISK_TIMEOUT_SCALE '1'
  
    /* active connection retries when C_WF_CONNECTION */
  #define DRBD_CONNECT_INT_MIN 1
  #define DRBD_CONNECT_INT_MAX 120
  #define DRBD_CONNECT_INT_DEF 10   /* seconds */
  #define DRBD_CONNECT_INT_SCALE '1'
  
    /* keep-alive probes when idle */
  #define DRBD_PING_INT_MIN 1
  #define DRBD_PING_INT_MAX 120
  #define DRBD_PING_INT_DEF 10
  #define DRBD_PING_INT_SCALE '1'
  
   /* timeout for the ping packets.*/
  #define DRBD_PING_TIMEO_MIN  1
  #define DRBD_PING_TIMEO_MAX  300
  #define DRBD_PING_TIMEO_DEF  5
  #define DRBD_PING_TIMEO_SCALE '1'
  
    /* max number of write requests between write barriers */
  #define DRBD_MAX_EPOCH_SIZE_MIN 1
  #define DRBD_MAX_EPOCH_SIZE_MAX 20000
  #define DRBD_MAX_EPOCH_SIZE_DEF 2048
  #define DRBD_MAX_EPOCH_SIZE_SCALE '1'
  
    /* I don't think that a tcp send buffer of more than 10M is useful */
  #define DRBD_SNDBUF_SIZE_MIN  0
  #define DRBD_SNDBUF_SIZE_MAX  (10<<20)
  #define DRBD_SNDBUF_SIZE_DEF  0
  #define DRBD_SNDBUF_SIZE_SCALE '1'
  
  #define DRBD_RCVBUF_SIZE_MIN  0
  #define DRBD_RCVBUF_SIZE_MAX  (10<<20)
  #define DRBD_RCVBUF_SIZE_DEF  0
  #define DRBD_RCVBUF_SIZE_SCALE '1'
  
    /* @4k PageSize -> 128kB - 512MB */
  #define DRBD_MAX_BUFFERS_MIN  32
  #define DRBD_MAX_BUFFERS_MAX  131072
  #define DRBD_MAX_BUFFERS_DEF  2048
  #define DRBD_MAX_BUFFERS_SCALE '1'
  
    /* @4k PageSize -> 4kB - 512MB */
  #define DRBD_UNPLUG_WATERMARK_MIN  1
  #define DRBD_UNPLUG_WATERMARK_MAX  131072
  #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
  #define DRBD_UNPLUG_WATERMARK_SCALE '1'
  
    /* 0 is disabled.
     * 200 should be more than enough even for very short timeouts */
  #define DRBD_KO_COUNT_MIN  0
  #define DRBD_KO_COUNT_MAX  200
  #define DRBD_KO_COUNT_DEF  7
  #define DRBD_KO_COUNT_SCALE '1'
  /* } */
  
  /* syncer { */
    /* FIXME allow rate to be zero? */
  #define DRBD_RESYNC_RATE_MIN 1
  /* channel bonding 10 GbE, or other hardware */
  #define DRBD_RESYNC_RATE_MAX (4 << 20)
  #define DRBD_RESYNC_RATE_DEF 250
  #define DRBD_RESYNC_RATE_SCALE 'k'  /* kilobytes */
  
    /* less than 7 would hit performance unnecessarily. */
  #define DRBD_AL_EXTENTS_MIN  7
    /* we use u16 as "slot number", (u16)~0 is "FREE".
     * If you use >= 292 kB on-disk ring buffer,
     * this is the maximum you can use: */
  #define DRBD_AL_EXTENTS_MAX  0xfffe
  #define DRBD_AL_EXTENTS_DEF  1237
  #define DRBD_AL_EXTENTS_SCALE '1'
  
  #define DRBD_MINOR_NUMBER_MIN  -1
  #define DRBD_MINOR_NUMBER_MAX  ((1 << 20) - 1)
  #define DRBD_MINOR_NUMBER_DEF  -1
  #define DRBD_MINOR_NUMBER_SCALE '1'
  
  /* } */
  
  /* drbdsetup XY resize -d Z
   * you are free to reduce the device size to nothing, if you want to.
   * the upper limit with 64bit kernel, enough ram and flexible meta data
   * is 1 PiB, currently. */
  /* DRBD_MAX_SECTORS */
  #define DRBD_DISK_SIZE_MIN  0
  #define DRBD_DISK_SIZE_MAX  (1 * (2LLU << 40))
  #define DRBD_DISK_SIZE_DEF  0 /* = disabled = no user size... */
  #define DRBD_DISK_SIZE_SCALE 's'  /* sectors */
  
  #define DRBD_ON_IO_ERROR_DEF EP_DETACH
  #define DRBD_FENCING_DEF FP_DONT_CARE
  #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
  #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
  #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
  #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
  #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
  #define DRBD_ON_CONGESTION_DEF OC_BLOCK
  #define DRBD_READ_BALANCING_DEF RB_PREFER_LOCAL
  
  #define DRBD_MAX_BIO_BVECS_MIN 0
  #define DRBD_MAX_BIO_BVECS_MAX 128
  #define DRBD_MAX_BIO_BVECS_DEF 0
  #define DRBD_MAX_BIO_BVECS_SCALE '1'
  
  #define DRBD_C_PLAN_AHEAD_MIN  0
  #define DRBD_C_PLAN_AHEAD_MAX  300
  #define DRBD_C_PLAN_AHEAD_DEF  20
  #define DRBD_C_PLAN_AHEAD_SCALE '1'
  
  #define DRBD_C_DELAY_TARGET_MIN 1
  #define DRBD_C_DELAY_TARGET_MAX 100
  #define DRBD_C_DELAY_TARGET_DEF 10
  #define DRBD_C_DELAY_TARGET_SCALE '1'
  
  #define DRBD_C_FILL_TARGET_MIN 0
  #define DRBD_C_FILL_TARGET_MAX (1<<20) /* 500MByte in sec */
  #define DRBD_C_FILL_TARGET_DEF 100 /* Try to place 50KiB in socket send buffer during resync */
  #define DRBD_C_FILL_TARGET_SCALE 's'  /* sectors */
  
  #define DRBD_C_MAX_RATE_MIN     250
  #define DRBD_C_MAX_RATE_MAX     (4 << 20)
  #define DRBD_C_MAX_RATE_DEF     102400
  #define DRBD_C_MAX_RATE_SCALE	'k'  /* kilobytes */
  
  #define DRBD_C_MIN_RATE_MIN     0
  #define DRBD_C_MIN_RATE_MAX     (4 << 20)
  #define DRBD_C_MIN_RATE_DEF     250
  #define DRBD_C_MIN_RATE_SCALE	'k'  /* kilobytes */
  
  #define DRBD_CONG_FILL_MIN	0
  #define DRBD_CONG_FILL_MAX	(10<<21) /* 10GByte in sectors */
  #define DRBD_CONG_FILL_DEF	0
  #define DRBD_CONG_FILL_SCALE	's'  /* sectors */
  
  #define DRBD_CONG_EXTENTS_MIN	DRBD_AL_EXTENTS_MIN
  #define DRBD_CONG_EXTENTS_MAX	DRBD_AL_EXTENTS_MAX
  #define DRBD_CONG_EXTENTS_DEF	DRBD_AL_EXTENTS_DEF
  #define DRBD_CONG_EXTENTS_SCALE DRBD_AL_EXTENTS_SCALE
  
  #define DRBD_PROTOCOL_DEF DRBD_PROT_C
  
  #define DRBD_DISK_BARRIER_DEF	0
  #define DRBD_DISK_FLUSHES_DEF	1
  #define DRBD_DISK_DRAIN_DEF	1
  #define DRBD_MD_FLUSHES_DEF	1
  #define DRBD_TCP_CORK_DEF	1
  #define DRBD_AL_UPDATES_DEF     1
  
  #define DRBD_ALLOW_TWO_PRIMARIES_DEF	0
  #define DRBD_ALWAYS_ASBP_DEF	0
  #define DRBD_USE_RLE_DEF	1
  #define DRBD_CSUMS_AFTER_CRASH_ONLY_DEF 0
  
  #define DRBD_AL_STRIPES_MIN     1
  #define DRBD_AL_STRIPES_MAX     1024
  #define DRBD_AL_STRIPES_DEF     1
  #define DRBD_AL_STRIPES_SCALE   '1'
  
  #define DRBD_AL_STRIPE_SIZE_MIN   4
  #define DRBD_AL_STRIPE_SIZE_MAX   16777216
  #define DRBD_AL_STRIPE_SIZE_DEF   32
  #define DRBD_AL_STRIPE_SIZE_SCALE 'k' /* kilobytes */
  
  #define DRBD_SOCKET_CHECK_TIMEO_MIN 0
  #define DRBD_SOCKET_CHECK_TIMEO_MAX DRBD_PING_TIMEO_MAX
  #define DRBD_SOCKET_CHECK_TIMEO_DEF 0
  #define DRBD_SOCKET_CHECK_TIMEO_SCALE '1'
  #endif