writeback: split writeback_inodes_wb
[linux-2.6/next.git] / include / linux / drbd_limits.h
blob440b42e38e898278c7e4742e29cc578add0840e1
1 /*
2 drbd_limits.h
3 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
4 */
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.
13 #ifndef DRBD_LIMITS_H
14 #define DRBD_LIMITS_H 1
16 #define DEBUG_RANGE_CHECK 0
18 #define DRBD_MINOR_COUNT_MIN 1
19 #define DRBD_MINOR_COUNT_MAX 255
21 #define DRBD_DIALOG_REFRESH_MIN 0
22 #define DRBD_DIALOG_REFRESH_MAX 600
24 /* valid port number */
25 #define DRBD_PORT_MIN 1
26 #define DRBD_PORT_MAX 0xffff
28 /* startup { */
29 /* if you want more than 3.4 days, disable */
30 #define DRBD_WFC_TIMEOUT_MIN 0
31 #define DRBD_WFC_TIMEOUT_MAX 300000
32 #define DRBD_WFC_TIMEOUT_DEF 0
34 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
35 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
36 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
38 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
39 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
40 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
41 /* }*/
43 /* net { */
44 /* timeout, unit centi seconds
45 * more than one minute timeout is not usefull */
46 #define DRBD_TIMEOUT_MIN 1
47 #define DRBD_TIMEOUT_MAX 600
48 #define DRBD_TIMEOUT_DEF 60 /* 6 seconds */
50 /* active connection retries when C_WF_CONNECTION */
51 #define DRBD_CONNECT_INT_MIN 1
52 #define DRBD_CONNECT_INT_MAX 120
53 #define DRBD_CONNECT_INT_DEF 10 /* seconds */
55 /* keep-alive probes when idle */
56 #define DRBD_PING_INT_MIN 1
57 #define DRBD_PING_INT_MAX 120
58 #define DRBD_PING_INT_DEF 10
60 /* timeout for the ping packets.*/
61 #define DRBD_PING_TIMEO_MIN 1
62 #define DRBD_PING_TIMEO_MAX 100
63 #define DRBD_PING_TIMEO_DEF 5
65 /* max number of write requests between write barriers */
66 #define DRBD_MAX_EPOCH_SIZE_MIN 1
67 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
68 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
70 /* I don't think that a tcp send buffer of more than 10M is usefull */
71 #define DRBD_SNDBUF_SIZE_MIN 0
72 #define DRBD_SNDBUF_SIZE_MAX (10<<20)
73 #define DRBD_SNDBUF_SIZE_DEF 0
75 #define DRBD_RCVBUF_SIZE_MIN 0
76 #define DRBD_RCVBUF_SIZE_MAX (10<<20)
77 #define DRBD_RCVBUF_SIZE_DEF 0
79 /* @4k PageSize -> 128kB - 512MB */
80 #define DRBD_MAX_BUFFERS_MIN 32
81 #define DRBD_MAX_BUFFERS_MAX 131072
82 #define DRBD_MAX_BUFFERS_DEF 2048
84 /* @4k PageSize -> 4kB - 512MB */
85 #define DRBD_UNPLUG_WATERMARK_MIN 1
86 #define DRBD_UNPLUG_WATERMARK_MAX 131072
87 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
89 /* 0 is disabled.
90 * 200 should be more than enough even for very short timeouts */
91 #define DRBD_KO_COUNT_MIN 0
92 #define DRBD_KO_COUNT_MAX 200
93 #define DRBD_KO_COUNT_DEF 0
94 /* } */
96 /* syncer { */
97 /* FIXME allow rate to be zero? */
98 #define DRBD_RATE_MIN 1
99 /* channel bonding 10 GbE, or other hardware */
100 #define DRBD_RATE_MAX (4 << 20)
101 #define DRBD_RATE_DEF 250 /* kb/second */
103 /* less than 7 would hit performance unneccessarily.
104 * 3833 is the largest prime that still does fit
105 * into 64 sectors of activity log */
106 #define DRBD_AL_EXTENTS_MIN 7
107 #define DRBD_AL_EXTENTS_MAX 3833
108 #define DRBD_AL_EXTENTS_DEF 127
110 #define DRBD_AFTER_MIN -1
111 #define DRBD_AFTER_MAX 255
112 #define DRBD_AFTER_DEF -1
114 /* } */
116 /* drbdsetup XY resize -d Z
117 * you are free to reduce the device size to nothing, if you want to.
118 * the upper limit with 64bit kernel, enough ram and flexible meta data
119 * is 16 TB, currently. */
120 /* DRBD_MAX_SECTORS */
121 #define DRBD_DISK_SIZE_SECT_MIN 0
122 #define DRBD_DISK_SIZE_SECT_MAX (16 * (2LLU << 30))
123 #define DRBD_DISK_SIZE_SECT_DEF 0 /* = disabled = no user size... */
125 #define DRBD_ON_IO_ERROR_DEF EP_PASS_ON
126 #define DRBD_FENCING_DEF FP_DONT_CARE
127 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
128 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
129 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
130 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
132 #define DRBD_MAX_BIO_BVECS_MIN 0
133 #define DRBD_MAX_BIO_BVECS_MAX 128
134 #define DRBD_MAX_BIO_BVECS_DEF 0
136 #define DRBD_DP_VOLUME_MIN 4
137 #define DRBD_DP_VOLUME_MAX 1048576
138 #define DRBD_DP_VOLUME_DEF 16384
140 #define DRBD_DP_INTERVAL_MIN 1
141 #define DRBD_DP_INTERVAL_MAX 600
142 #define DRBD_DP_INTERVAL_DEF 5
144 #define DRBD_RS_THROTTLE_TH_MIN 1
145 #define DRBD_RS_THROTTLE_TH_MAX 600
146 #define DRBD_RS_THROTTLE_TH_DEF 20
148 #define DRBD_RS_HOLD_OFF_TH_MIN 1
149 #define DRBD_RS_HOLD_OFF_TH_MAX 6000
150 #define DRBD_RS_HOLD_OFF_TH_DEF 100
152 #undef RANGE
153 #endif