1PMEMPOOL_CHECK_INIT(3)     PMDK Programmer's Manual     PMEMPOOL_CHECK_INIT(3)
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NAME

6       pmempool_check_init(),  pmempool_check(), pmempool_check_end() - checks
7       pmempool health
8

SYNOPSIS

10              #include <libpmempool.h>
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12              PMEMpoolcheck *pmempool_check_init(struct pmempool_check_args *args,
13                  size_t args_size);
14              struct pmempool_check_status *pmempool_check(PMEMpoolcheck *ppc);
15              enum pmempool_check_result pmempool_check_end(PMEMpoolcheck *ppc);
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DESCRIPTION

18       To perform the checks provided by libpmempool,  a  check  context  must
19       first be initialized using the pmempool_check_init() function described
20       in this section.  Once initialized, the check context is represented by
21       an  opaque handle of type PMEMpoolcheck*, which is passed to all of the
22       other functions available in libpmempool
23
24       To execute checks, pmempool_check() must be called  iteratively.   Each
25       call  generates  a  new  check  status,  represented  by a struct pmem‐
26       pool_check_status structure.  Status messages are described  later  be‐
27       low.
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29       When  the  checks  are  completed,  pmempool_check() returns NULL.  The
30       check must be finalized using pmempool_check_end(),  which  returns  an
31       enum pmempool_check_result describing the results of the entire check.
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33       pmempool_check_init()  initializes  the  check context.  args describes
34       parameters of the check context.  args_size should be equal to the size
35       of  the  struct pmempool_check_args.  struct pmempool_check_args is de‐
36       fined as follows:
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38              struct pmempool_check_args
39              {
40                  /* path to the pool to check */
41                  const char *path;
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43                  /* optional backup path */
44                  const char *backup_path;
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46                  /* type of the pool */
47                  enum pmempool_pool_type pool_type;
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49                  /* parameters */
50                  int flags;
51              };
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53       The flags argument accepts any  combination  of  the  following  values
54       (ORed):
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56       · PMEMPOOL_CHECK_REPAIR - perform repairs
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58       · PMEMPOOL_CHECK_DRY_RUN - emulate repairs, not supported on Device DAX
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60       · PMEMPOOL_CHECK_ADVANCED - perform hazardous repairs
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62       · PMEMPOOL_CHECK_ALWAYS_YES - do not ask before repairs
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64       · PMEMPOOL_CHECK_VERBOSE - generate info statuses
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66       · PMEMPOOL_CHECK_FORMAT_STR - generate string format statuses
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68       pool_type  must  match the type of the pool being processed.  Pool type
69       detection may be enabled by setting pool_type to PMEMPOOL_POOL_TYPE_DE‐
70       TECT.  A pool type detection failure ends the check.
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72       backup_path may be:
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74       · NULL.  No backup will be performed.
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76       · a  non-existent  file: backup_path will be created and backup will be
77         performed.  path must be a single file pool.
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79       · an existing pool set file: Backup will be performed as defined by the
80         backup_path  pool set.  path must be a pool set, and backup_path must
81         have the same structure (the same number of parts  with  exactly  the
82         same size) as the path pool set.
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84       Backup  is  supported only if the source pool set has no defined repli‐
85       cas.
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87       Neither path nor backup_path may specify a pool set with remote  repli‐
88       cas.
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90       The  pmempool_check() function starts or resumes the check indicated by
91       ppc.  When the next status is generated, the check is paused and  pmem‐
92       pool_check()  returns  a  pointer  to  the struct pmempool_check_status
93       structure:
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95              struct pmempool_check_status
96              {
97                  enum pmempool_check_msg_type type; /* type of the status */
98                  struct
99                  {
100                      const char *msg; /* status message string */
101                      const char *answer; /* answer to message if applicable */
102                  } str;
103              };
104
105       This structure can describe three types of statuses:
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107       · PMEMPOOL_CHECK_MSG_TYPE_INFO - detailed information about the  check.
108         Generated only if a PMEMPOOL_CHECK_VERBOSE flag was set.
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110       · PMEMPOOL_CHECK_MSG_TYPE_ERROR - An error was encountered.
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112       · PMEMPOOL_CHECK_MSG_TYPE_QUESTION  -  question.   Generated only if an
113         PMEMPOOL_CHECK_ALWAYS_YES flag was not set.  It requires answer to be
114         set to “yes” or “no” before continuing.
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116       After  calling  pmempool_check()  again, the previously provided struct
117       pmempool_check_status pointer must be considered invalid.
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119       The pmempool_check_end() function finalizes the check and releases  all
120       related resources.  ppc is invalid after calling pmempool_check_end().
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RETURN VALUE

123       pmempool_check_init()  returns an opaque handle of type PMEMpoolcheck*.
124       If the provided parameters are invalid or  the  initialization  process
125       fails, pmempool_check_init() returns NULL and sets errno appropriately.
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127       Each  call  to  pmempool_check()  returns  a  pointer to a struct pmem‐
128       pool_check_status structure when a status is generated.  When the check
129       completes, pmempool_check() returns NULL.
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131       The pmempool_check_end() function returns an enum pmempool_check_result
132       summarizing the results of the finalized  check.   pmempool_check_end()
133       can return one of the following values:
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135       · PMEMPOOL_CHECK_RESULT_CONSISTENT - the pool is consistent
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137       · PMEMPOOL_CHECK_RESULT_NOT_CONSISTENT - the pool is not consistent
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139       · PMEMPOOL_CHECK_RESULT_REPAIRED  -  the pool has issues but all repair
140         steps completed successfully
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142       · PMEMPOOL_CHECK_RESULT_CANNOT_REPAIR - the pool has issues  which  can
143         not be repaired
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145       · PMEMPOOL_CHECK_RESULT_ERROR  -  the  pool has errors or the check en‐
146         countered an issue
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148       · PMEMPOOL_CHECK_RESULT_SYNC_REQ - the pool has single healthy replica.
149         To fix remaining issues use pmempool_sync(3).
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EXAMPLE

152       This is an example of a check context initialization:
153
154              struct pmempool_check_args args =
155              {
156                  .path = "/path/to/blk.pool",
157                  .backup_path = NULL,
158                  .pool_type = PMEMPOOL_POOL_TYPE_BLK,
159                  .flags = PMEMPOOL_CHECK_REPAIR | PMEMPOOL_CHECK_DRY_RUN |
160                      PMEMPOOL_CHECK_VERBOSE | PMEMPOOL_CHECK_FORMAT_STR
161              };
162
163              PMEMpoolcheck *ppc = pmempool_check_init(&args, sizeof(args));
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165       The check will process a pool of type PMEMPOOL_POOL_TYPE_BLK located in
166       the path /path/to/blk.pool.  Before the check  it  will  not  create  a
167       backup  of  the pool (backup_path == NULL).  If the check finds any is‐
168       sues it will try to perform repair steps  (PMEMPOOL_CHECK_REPAIR),  but
169       it  will  not make any changes to the pool (PMEMPOOL_CHECK_DRY_RUN) and
170       it will not perform any dangerous repair steps  (no  PMEMPOOL_CHECK_AD‐
171       VANCED).   The  check  will  ask before performing any repair steps (no
172       PMEMPOOL_CHECK_ALWAYS_YES).  It will also generate detailed information
173       about  the  check  (PMEMPOOL_CHECK_VERBOSE).   The  PMEMPOOL_CHECK_FOR‐
174       MAT_STR  flag  indicates   string   format   statuses   (struct   pmem‐
175       pool_check_status).  Currently this is the only supported status format
176       so this flag is required.
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NOTES

179       Currently, checking the consistency of a pmemobj pool is not supported.
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SEE ALSO

182       libpmemlog(7), libpmemobj(7) and <http://pmem.io>
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186PMDK - pmempool API version 1.3   2018-09-17            PMEMPOOL_CHECK_INIT(3)
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