src/proc_diskstats.c

   1 #include "common.h"
   2
   3 #define RRD_TYPE_DISK "disk"
   4
   5 #define DISK_TYPE_PHYSICAL  1
   6 #define DISK_TYPE_PARTITION 2
   7 #define DISK_TYPE_CONTAINER 3
   8
   9 static struct disk {
  10     char *disk;             // the name of the disk (sda, sdb, etc)
  11     unsigned long major;
  12     unsigned long minor;
  13     int sector_size;
  14     int type;
  15
  16     char *mount_point;
  17
  18     // disk options caching
  19     int configured;
  20     int do_io;
  21     int do_ops;
  22     int do_mops;
  23     int do_iotime;
  24     int do_qops;
  25     int do_util;
  26     int do_backlog;
  27
  28     struct disk *next;
  29 } *disk_root = NULL;
  30
  31 static struct disk *get_disk(unsigned long major, unsigned long minor, char *disk) {
  32     static char path_to_get_hw_sector_size[FILENAME_MAX + 1] = "";
  33     static char path_to_get_hw_sector_size_partitions[FILENAME_MAX + 1] = "";
  34     static char path_find_block_device[FILENAME_MAX + 1] = "";
  35     static struct mountinfo *disk_mountinfo_root = NULL;
  36
  37     struct disk *d;
  38
  39     // search for it in our RAM list.
  40     // this is sequential, but since we just walk through
  41     // and the number of disks / partitions in a system
  42     // should not be that many, it should be acceptable
  43     for(d = disk_root; d ; d = d->next)
  44         if(unlikely(d->major == major && d->minor == minor))
  45             return d;
  46
  47     // not found
  48     // create a new disk structure
  49     d = (struct disk *)mallocz(sizeof(struct disk));
  50
  51     d->disk = strdupz(disk);
  52     d->major = major;
  53     d->minor = minor;
  54     d->type = DISK_TYPE_PHYSICAL; // Default type. Changed later if not correct.
  55     d->configured = 0;
  56     d->sector_size = 512; // the default, will be changed below
  57     d->next = NULL;
  58
  59     // append it to the list
  60     if(unlikely(!disk_root))
  61         disk_root = d;
  62     else {
  63         struct disk *last;
  64         for(last = disk_root; last->next ;last = last->next);
  65         last->next = d;
  66     }
  67
  68     // ------------------------------------------------------------------------
  69     // find the type of the device
  70
  71     char buffer[FILENAME_MAX + 1];
  72
  73     // get the default path for finding info about the block device
  74     if(unlikely(!path_find_block_device[0])) {
  75         snprintfz(buffer, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/dev/block/%lu:%lu/%s");
  76         snprintfz(path_find_block_device, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get block device infos", buffer));
  77     }
  78
  79     // find if it is a partition
  80     // by checking if /sys/dev/block/MAJOR:MINOR/partition is readable.
  81     snprintfz(buffer, FILENAME_MAX, path_find_block_device, major, minor, "partition");
  82     if(likely(access(buffer, R_OK) == 0)) {
  83         d->type = DISK_TYPE_PARTITION;
  84     }
  85     else {
  86         // find if it is a container
  87         // by checking if /sys/dev/block/MAJOR:MINOR/slaves has entries
  88         snprintfz(buffer, FILENAME_MAX, path_find_block_device, major, minor, "slaves/");
  89         DIR *dirp = opendir(buffer);
  90         if(likely(dirp != NULL)) {
  91             struct dirent *dp;
  92             while( (dp = readdir(dirp)) ) {
  93                 // . and .. are also files in empty folders.
  94                 if(unlikely(strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0)) {
  95                     continue;
  96                 }
  97
  98                 d->type = DISK_TYPE_CONTAINER;
  99
 100                 // Stop the loop after we found one file.
 101                 break;
 102             }
 103             if(unlikely(closedir(dirp) == -1))
 104                 error("Unable to close dir %s", buffer);
 105         }
 106     }
 107
 108     // ------------------------------------------------------------------------
 109     // check if we can find its mount point
 110
 111     // mountinfo_find() can be called with NULL disk_mountinfo_root
 112     struct mountinfo *mi = mountinfo_find(disk_mountinfo_root, d->major, d->minor);
 113     if(unlikely(!mi)) {
 114         // mountinfo_free can be called with NULL
 115         mountinfo_free(disk_mountinfo_root);
 116         disk_mountinfo_root = mountinfo_read(0);
 117         mi = mountinfo_find(disk_mountinfo_root, d->major, d->minor);
 118     }
 119
 120     if(unlikely(mi))
 121         d->mount_point = strdupz(mi->mount_point);
 122     else
 123         d->mount_point = NULL;
 124
 125     // ------------------------------------------------------------------------
 126     // find the disk sector size
 127
 128     if(unlikely(!path_to_get_hw_sector_size[0])) {
 129         snprintfz(buffer, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/block/%s/queue/hw_sector_size");
 130         snprintfz(path_to_get_hw_sector_size, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get h/w sector size", buffer));
 131     }
 132     if(unlikely(!path_to_get_hw_sector_size_partitions[0])) {
 133         snprintfz(buffer, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/dev/block/%lu:%lu/subsystem/%s/../queue/hw_sector_size");
 134         snprintfz(path_to_get_hw_sector_size_partitions, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get h/w sector size for partitions", buffer));
 135     }
 136
 137     {
 138         char tf[FILENAME_MAX + 1], *t;
 139         strncpyz(tf, d->disk, FILENAME_MAX);
 140
 141         // replace all / with !
 142         for(t = tf; *t ;t++)
 143             if(unlikely(*t == '/')) *t = '!';
 144
 145         if(likely(d->type == DISK_TYPE_PARTITION))
 146             snprintfz(buffer, FILENAME_MAX, path_to_get_hw_sector_size_partitions, d->major, d->minor, tf);
 147         else
 148             snprintfz(buffer, FILENAME_MAX, path_to_get_hw_sector_size, tf);
 149
 150         FILE *fpss = fopen(buffer, "r");
 151         if(likely(fpss)) {
 152             char buffer2[1024 + 1];
 153             char *tmp = fgets(buffer2, 1024, fpss);
 154
 155             if(likely(tmp)) {
 156                 d->sector_size = str2i(tmp);
 157                 if(unlikely(d->sector_size <= 0)) {
 158                     error("Invalid sector size %d for device %s in %s. Assuming 512.", d->sector_size, d->disk, buffer);
 159                     d->sector_size = 512;
 160                 }
 161             }
 162             else error("Cannot read data for sector size for device %s from %s. Assuming 512.", d->disk, buffer);
 163
 164             fclose(fpss);
 165         }
 166         else error("Cannot read sector size for device %s from %s. Assuming 512.", d->disk, buffer);
 167     }
 168
 169     return d;
 170 }
 171
 172 static inline int is_major_enabled(int major) {
 173     static char *major_configs = NULL;
 174     static size_t major_size = 0;
 175
 176     if(major < 0) return 1;
 177
 178     size_t wanted_size = (size_t)major + 1;
 179
 180     if(major_size < wanted_size) {
 181         major_configs = reallocz(major_configs, wanted_size);
 182
 183         size_t i;
 184         for(i = major_size; i < wanted_size ; i++)
 185             major_configs[i] = -1;
 186
 187         major_size = wanted_size;
 188     }
 189
 190     if(major_configs[major] == -1) {
 191         char buffer[CONFIG_MAX_NAME + 1];
 192         snprintfz(buffer, CONFIG_MAX_NAME, "performance metrics for disks with major %d", major);
 193         major_configs[major] = (char)config_get_boolean("plugin:proc:/proc/diskstats", buffer, 1);
 194     }
 195
 196     return major_configs[major];
 197 }
 198
 199 int do_proc_diskstats(int update_every, usec_t dt) {
 200     (void)dt;
 201
 202     static procfile *ff = NULL;
 203     static int  global_enable_new_disks_detected_at_runtime = CONFIG_ONDEMAND_YES,
 204                 global_enable_performance_for_physical_disks = CONFIG_ONDEMAND_ONDEMAND,
 205                 global_enable_performance_for_virtual_disks = CONFIG_ONDEMAND_ONDEMAND,
 206                 global_enable_performance_for_partitions = CONFIG_ONDEMAND_NO,
 207                 global_do_io = CONFIG_ONDEMAND_ONDEMAND,
 208                 global_do_ops = CONFIG_ONDEMAND_ONDEMAND,
 209                 global_do_mops = CONFIG_ONDEMAND_ONDEMAND,
 210                 global_do_iotime = CONFIG_ONDEMAND_ONDEMAND,
 211                 global_do_qops = CONFIG_ONDEMAND_ONDEMAND,
 212                 global_do_util = CONFIG_ONDEMAND_ONDEMAND,
 213                 global_do_backlog = CONFIG_ONDEMAND_ONDEMAND,
 214                 globals_initialized = 0;
 215
 216     if(unlikely(!globals_initialized)) {
 217         global_enable_new_disks_detected_at_runtime = config_get_boolean("plugin:proc:/proc/diskstats", "enable new disks detected at runtime", global_enable_new_disks_detected_at_runtime);
 218
 219         global_enable_performance_for_physical_disks = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "performance metrics for physical disks", global_enable_performance_for_physical_disks);
 220         global_enable_performance_for_virtual_disks = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "performance metrics for virtual disks", global_enable_performance_for_virtual_disks);
 221         global_enable_performance_for_partitions = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "performance metrics for partitions", global_enable_performance_for_partitions);
 222
 223         global_do_io      = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "bandwidth for all disks", global_do_io);
 224         global_do_ops     = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "operations for all disks", global_do_ops);
 225         global_do_mops    = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "merged operations for all disks", global_do_mops);
 226         global_do_iotime  = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "i/o time for all disks", global_do_iotime);
 227         global_do_qops    = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "queued operations for all disks", global_do_qops);
 228         global_do_util    = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "utilization percentage for all disks", global_do_util);
 229         global_do_backlog = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "backlog for all disks", global_do_backlog);
 230
 231         globals_initialized = 1;
 232     }
 233
 234     // --------------------------------------------------------------------------
 235
 236     if(unlikely(!ff)) {
 237         char filename[FILENAME_MAX + 1];
 238         snprintfz(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/diskstats");
 239         ff = procfile_open(config_get("plugin:proc:/proc/diskstats", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
 240     }
 241     if(unlikely(!ff)) return 0;
 242
 243     ff = procfile_readall(ff);
 244     if(unlikely(!ff)) return 0; // we return 0, so that we will retry to open it next time
 245
 246     size_t lines = procfile_lines(ff), l;
 247
 248     for(l = 0; l < lines ;l++) {
 249         // --------------------------------------------------------------------------
 250         // Read parameters
 251
 252         char *disk;
 253         unsigned long       major = 0, minor = 0;
 254
 255         collected_number    reads = 0,  mreads = 0,  readsectors = 0,  readms = 0,
 256                             writes = 0, mwrites = 0, writesectors = 0, writems = 0,
 257                             queued_ios = 0, busy_ms = 0, backlog_ms = 0;
 258
 259         collected_number    last_reads = 0,  last_readsectors = 0,  last_readms = 0,
 260                             last_writes = 0, last_writesectors = 0, last_writems = 0,
 261                             last_busy_ms = 0;
 262
 263         size_t words = procfile_linewords(ff, l);
 264         if(unlikely(words < 14)) continue;
 265
 266         major           = str2ul(procfile_lineword(ff, l, 0));
 267         minor           = str2ul(procfile_lineword(ff, l, 1));
 268         disk            = procfile_lineword(ff, l, 2);
 269
 270         // # of reads completed # of writes completed
 271         // This is the total number of reads or writes completed successfully.
 272         reads           = str2ull(procfile_lineword(ff, l, 3));  // rd_ios
 273         writes          = str2ull(procfile_lineword(ff, l, 7));  // wr_ios
 274
 275         // # of reads merged # of writes merged
 276         // Reads and writes which are adjacent to each other may be merged for
 277         // efficiency.  Thus two 4K reads may become one 8K read before it is
 278         // ultimately handed to the disk, and so it will be counted (and queued)
 279         mreads          = str2ull(procfile_lineword(ff, l, 4));  // rd_merges_or_rd_sec
 280         mwrites         = str2ull(procfile_lineword(ff, l, 8));  // wr_merges
 281
 282         // # of sectors read # of sectors written
 283         // This is the total number of sectors read or written successfully.
 284         readsectors     = str2ull(procfile_lineword(ff, l, 5));  // rd_sec_or_wr_ios
 285         writesectors    = str2ull(procfile_lineword(ff, l, 9));  // wr_sec
 286
 287         // # of milliseconds spent reading # of milliseconds spent writing
 288         // This is the total number of milliseconds spent by all reads or writes (as
 289         // measured from __make_request() to end_that_request_last()).
 290         readms          = str2ull(procfile_lineword(ff, l, 6));  // rd_ticks_or_wr_sec
 291         writems         = str2ull(procfile_lineword(ff, l, 10)); // wr_ticks
 292
 293         // # of I/Os currently in progress
 294         // The only field that should go to zero. Incremented as requests are
 295         // given to appropriate struct request_queue and decremented as they finish.
 296         queued_ios      = str2ull(procfile_lineword(ff, l, 11)); // ios_pgr
 297
 298         // # of milliseconds spent doing I/Os
 299         // This field increases so long as field queued_ios is nonzero.
 300         busy_ms         = str2ull(procfile_lineword(ff, l, 12)); // tot_ticks
 301
 302         // weighted # of milliseconds spent doing I/Os
 303         // This field is incremented at each I/O start, I/O completion, I/O
 304         // merge, or read of these stats by the number of I/Os in progress
 305         // (field queued_ios) times the number of milliseconds spent doing I/O since the
 306         // last update of this field.  This can provide an easy measure of both
 307         // I/O completion time and the backlog that may be accumulating.
 308         backlog_ms      = str2ull(procfile_lineword(ff, l, 13)); // rq_ticks
 309
 310
 311         // --------------------------------------------------------------------------
 312         // remove slashes from disk names
 313         char *s;
 314         for(s = disk; *s ;s++)
 315             if(*s == '/') *s = '_';
 316
 317         // --------------------------------------------------------------------------
 318         // get a disk structure for the disk
 319
 320         struct disk *d = get_disk(major, minor, disk);
 321
 322
 323         // --------------------------------------------------------------------------
 324         // Set its family based on mount point
 325
 326         char *family = d->mount_point;
 327         if(!family) family = disk;
 328
 329
 330         // --------------------------------------------------------------------------
 331         // Check the configuration for the device
 332
 333         if(unlikely(!d->configured)) {
 334             char var_name[4096 + 1];
 335             snprintfz(var_name, 4096, "plugin:proc:/proc/diskstats:%s", disk);
 336
 337             int def_enable = config_get_boolean_ondemand(var_name, "enable", global_enable_new_disks_detected_at_runtime);
 338             if(unlikely(def_enable == CONFIG_ONDEMAND_NO)) {
 339                 // the user does not want any metrics for this disk
 340                 d->do_io = CONFIG_ONDEMAND_NO;
 341                 d->do_ops = CONFIG_ONDEMAND_NO;
 342                 d->do_mops = CONFIG_ONDEMAND_NO;
 343                 d->do_iotime = CONFIG_ONDEMAND_NO;
 344                 d->do_qops = CONFIG_ONDEMAND_NO;
 345                 d->do_util = CONFIG_ONDEMAND_NO;
 346                 d->do_backlog = CONFIG_ONDEMAND_NO;
 347             }
 348             else {
 349                 // this disk is enabled
 350                 // check its direct settings
 351
 352                 int def_performance = CONFIG_ONDEMAND_ONDEMAND;
 353
 354                 // since this is 'on demand' we can figure the performance settings
 355                 // based on the type of disk
 356
 357                 switch(d->type) {
 358                     case DISK_TYPE_PHYSICAL:
 359                         def_performance = global_enable_performance_for_physical_disks;
 360                         break;
 361
 362                     case DISK_TYPE_PARTITION:
 363                         def_performance = global_enable_performance_for_partitions;
 364                         break;
 365
 366                     case DISK_TYPE_CONTAINER:
 367                         def_performance = global_enable_performance_for_virtual_disks;
 368                         break;
 369                 }
 370
 371                 // check if we have to disable performance for this disk
 372                 if(def_performance)
 373                     def_performance = is_major_enabled((int)major);
 374
 375                 // ------------------------------------------------------------
 376                 // now we have def_performance and def_space
 377                 // to work further
 378
 379                 // def_performance
 380                 // check the user configuration (this will also show our 'on demand' decision)
 381                 def_performance = config_get_boolean_ondemand(var_name, "enable performance metrics", def_performance);
 382
 383                 int ddo_io = CONFIG_ONDEMAND_NO,
 384                     ddo_ops = CONFIG_ONDEMAND_NO,
 385                     ddo_mops = CONFIG_ONDEMAND_NO,
 386                     ddo_iotime = CONFIG_ONDEMAND_NO,
 387                     ddo_qops = CONFIG_ONDEMAND_NO,
 388                     ddo_util = CONFIG_ONDEMAND_NO,
 389                     ddo_backlog = CONFIG_ONDEMAND_NO;
 390
 391                 // we enable individual performance charts only when def_performance is not disabled
 392                 if(unlikely(def_performance != CONFIG_ONDEMAND_NO)) {
 393                     ddo_io = global_do_io,
 394                     ddo_ops = global_do_ops,
 395                     ddo_mops = global_do_mops,
 396                     ddo_iotime = global_do_iotime,
 397                     ddo_qops = global_do_qops,
 398                     ddo_util = global_do_util,
 399                     ddo_backlog = global_do_backlog;
 400                 }
 401
 402                 d->do_io      = config_get_boolean_ondemand(var_name, "bandwidth", ddo_io);
 403                 d->do_ops     = config_get_boolean_ondemand(var_name, "operations", ddo_ops);
 404                 d->do_mops    = config_get_boolean_ondemand(var_name, "merged operations", ddo_mops);
 405                 d->do_iotime  = config_get_boolean_ondemand(var_name, "i/o time", ddo_iotime);
 406                 d->do_qops    = config_get_boolean_ondemand(var_name, "queued operations", ddo_qops);
 407                 d->do_util    = config_get_boolean_ondemand(var_name, "utilization percentage", ddo_util);
 408                 d->do_backlog = config_get_boolean_ondemand(var_name, "backlog", ddo_backlog);
 409             }
 410
 411             d->configured = 1;
 412         }
 413
 414         RRDSET *st;
 415
 416         // --------------------------------------------------------------------------
 417         // Do performance metrics
 418
 419         if(d->do_io == CONFIG_ONDEMAND_YES || (d->do_io == CONFIG_ONDEMAND_ONDEMAND && (readsectors || writesectors))) {
 420             d->do_io = CONFIG_ONDEMAND_YES;
 421
 422             st = rrdset_find_bytype(RRD_TYPE_DISK, disk);
 423             if(unlikely(!st)) {
 424                 st = rrdset_create(RRD_TYPE_DISK, disk, NULL, family, "disk.io", "Disk I/O Bandwidth", "kilobytes/s", 2000, update_every, RRDSET_TYPE_AREA);
 425
 426                 rrddim_add(st, "reads", NULL, d->sector_size, 1024, RRDDIM_INCREMENTAL);
 427                 rrddim_add(st, "writes", NULL, d->sector_size * -1, 1024, RRDDIM_INCREMENTAL);
 428             }
 429             else rrdset_next(st);
 430
 431             last_readsectors  = rrddim_set(st, "reads", readsectors);
 432             last_writesectors = rrddim_set(st, "writes", writesectors);
 433             rrdset_done(st);
 434         }
 435
 436         // --------------------------------------------------------------------
 437
 438         if(d->do_ops == CONFIG_ONDEMAND_YES || (d->do_ops == CONFIG_ONDEMAND_ONDEMAND && (reads || writes))) {
 439             d->do_ops = CONFIG_ONDEMAND_YES;
 440
 441             st = rrdset_find_bytype("disk_ops", disk);
 442             if(unlikely(!st)) {
 443                 st = rrdset_create("disk_ops", disk, NULL, family, "disk.ops", "Disk Completed I/O Operations", "operations/s", 2001, update_every, RRDSET_TYPE_LINE);
 444                 st->isdetail = 1;
 445
 446                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 447                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 448             }
 449             else rrdset_next(st);
 450
 451             last_reads  = rrddim_set(st, "reads", reads);
 452             last_writes = rrddim_set(st, "writes", writes);
 453             rrdset_done(st);
 454         }
 455
 456         // --------------------------------------------------------------------
 457
 458         if(d->do_qops == CONFIG_ONDEMAND_YES || (d->do_qops == CONFIG_ONDEMAND_ONDEMAND && queued_ios)) {
 459             d->do_qops = CONFIG_ONDEMAND_YES;
 460
 461             st = rrdset_find_bytype("disk_qops", disk);
 462             if(unlikely(!st)) {
 463                 st = rrdset_create("disk_qops", disk, NULL, family, "disk.qops", "Disk Current I/O Operations", "operations", 2002, update_every, RRDSET_TYPE_LINE);
 464                 st->isdetail = 1;
 465
 466                 rrddim_add(st, "operations", NULL, 1, 1, RRDDIM_ABSOLUTE);
 467             }
 468             else rrdset_next(st);
 469
 470             rrddim_set(st, "operations", queued_ios);
 471             rrdset_done(st);
 472         }
 473
 474         // --------------------------------------------------------------------
 475
 476         if(d->do_backlog == CONFIG_ONDEMAND_YES || (d->do_backlog == CONFIG_ONDEMAND_ONDEMAND && backlog_ms)) {
 477             d->do_backlog = CONFIG_ONDEMAND_YES;
 478
 479             st = rrdset_find_bytype("disk_backlog", disk);
 480             if(unlikely(!st)) {
 481                 st = rrdset_create("disk_backlog", disk, NULL, family, "disk.backlog", "Disk Backlog", "backlog (ms)", 2003, update_every, RRDSET_TYPE_AREA);
 482                 st->isdetail = 1;
 483
 484                 rrddim_add(st, "backlog", NULL, 1, 10, RRDDIM_INCREMENTAL);
 485             }
 486             else rrdset_next(st);
 487
 488             rrddim_set(st, "backlog", backlog_ms);
 489             rrdset_done(st);
 490         }
 491
 492         // --------------------------------------------------------------------
 493
 494         if(d->do_util == CONFIG_ONDEMAND_YES || (d->do_util == CONFIG_ONDEMAND_ONDEMAND && busy_ms)) {
 495             d->do_util = CONFIG_ONDEMAND_YES;
 496
 497             st = rrdset_find_bytype("disk_util", disk);
 498             if(unlikely(!st)) {
 499                 st = rrdset_create("disk_util", disk, NULL, family, "disk.util", "Disk Utilization Time", "% of time working", 2004, update_every, RRDSET_TYPE_AREA);
 500                 st->isdetail = 1;
 501
 502                 rrddim_add(st, "utilization", NULL, 1, 10, RRDDIM_INCREMENTAL);
 503             }
 504             else rrdset_next(st);
 505
 506             last_busy_ms = rrddim_set(st, "utilization", busy_ms);
 507             rrdset_done(st);
 508         }
 509
 510         // --------------------------------------------------------------------
 511
 512         if(d->do_mops == CONFIG_ONDEMAND_YES || (d->do_mops == CONFIG_ONDEMAND_ONDEMAND && (mreads || mwrites))) {
 513             d->do_mops = CONFIG_ONDEMAND_YES;
 514
 515             st = rrdset_find_bytype("disk_mops", disk);
 516             if(unlikely(!st)) {
 517                 st = rrdset_create("disk_mops", disk, NULL, family, "disk.mops", "Disk Merged Operations", "merged operations/s", 2021, update_every, RRDSET_TYPE_LINE);
 518                 st->isdetail = 1;
 519
 520                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 521                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 522             }
 523             else rrdset_next(st);
 524
 525             rrddim_set(st, "reads", mreads);
 526             rrddim_set(st, "writes", mwrites);
 527             rrdset_done(st);
 528         }
 529
 530         // --------------------------------------------------------------------
 531
 532         if(d->do_iotime == CONFIG_ONDEMAND_YES || (d->do_iotime == CONFIG_ONDEMAND_ONDEMAND && (readms || writems))) {
 533             d->do_iotime = CONFIG_ONDEMAND_YES;
 534
 535             st = rrdset_find_bytype("disk_iotime", disk);
 536             if(unlikely(!st)) {
 537                 st = rrdset_create("disk_iotime", disk, NULL, family, "disk.iotime", "Disk Total I/O Time", "milliseconds/s", 2022, update_every, RRDSET_TYPE_LINE);
 538                 st->isdetail = 1;
 539
 540                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 541                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 542             }
 543             else rrdset_next(st);
 544
 545             last_readms  = rrddim_set(st, "reads", readms);
 546             last_writems = rrddim_set(st, "writes", writems);
 547             rrdset_done(st);
 548         }
 549
 550         // --------------------------------------------------------------------
 551         // calculate differential charts
 552         // only if this is not the first time we run
 553
 554         if(likely(dt)) {
 555             if( (d->do_iotime == CONFIG_ONDEMAND_YES || (d->do_iotime == CONFIG_ONDEMAND_ONDEMAND && (readms || writems))) &&
 556                 (d->do_ops    == CONFIG_ONDEMAND_YES || (d->do_ops    == CONFIG_ONDEMAND_ONDEMAND && (reads || writes)))) {
 557                 st = rrdset_find_bytype("disk_await", disk);
 558                 if(unlikely(!st)) {
 559                     st = rrdset_create("disk_await", disk, NULL, family, "disk.await", "Average Completed I/O Operation Time", "ms per operation", 2005, update_every, RRDSET_TYPE_LINE);
 560                     st->isdetail = 1;
 561
 562                     rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_ABSOLUTE);
 563                     rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_ABSOLUTE);
 564                 }
 565                 else rrdset_next(st);
 566
 567                 rrddim_set(st, "reads", (reads - last_reads) ? (readms - last_readms) / (reads - last_reads) : 0);
 568                 rrddim_set(st, "writes", (writes - last_writes) ? (writems - last_writems) / (writes - last_writes) : 0);
 569                 rrdset_done(st);
 570             }
 571
 572             if( (d->do_io  == CONFIG_ONDEMAND_YES || (d->do_io  == CONFIG_ONDEMAND_ONDEMAND && (readsectors || writesectors))) &&
 573                 (d->do_ops == CONFIG_ONDEMAND_YES || (d->do_ops == CONFIG_ONDEMAND_ONDEMAND && (reads || writes)))) {
 574                 st = rrdset_find_bytype("disk_avgsz", disk);
 575                 if(unlikely(!st)) {
 576                     st = rrdset_create("disk_avgsz", disk, NULL, family, "disk.avgsz", "Average Completed I/O Operation Bandwidth", "kilobytes per operation", 2006, update_every, RRDSET_TYPE_AREA);
 577                     st->isdetail = 1;
 578
 579                     rrddim_add(st, "reads", NULL, d->sector_size, 1024, RRDDIM_ABSOLUTE);
 580                     rrddim_add(st, "writes", NULL, d->sector_size * -1, 1024, RRDDIM_ABSOLUTE);
 581                 }
 582                 else rrdset_next(st);
 583
 584                 rrddim_set(st, "reads", (reads - last_reads) ? (readsectors - last_readsectors) / (reads - last_reads) : 0);
 585                 rrddim_set(st, "writes", (writes - last_writes) ? (writesectors - last_writesectors) / (writes - last_writes) : 0);
 586                 rrdset_done(st);
 587             }
 588
 589             if( (d->do_util == CONFIG_ONDEMAND_YES || (d->do_util == CONFIG_ONDEMAND_ONDEMAND && busy_ms)) &&
 590                 (d->do_ops  == CONFIG_ONDEMAND_YES || (d->do_ops  == CONFIG_ONDEMAND_ONDEMAND && (reads || writes)))) {
 591                 st = rrdset_find_bytype("disk_svctm", disk);
 592                 if(unlikely(!st)) {
 593                     st = rrdset_create("disk_svctm", disk, NULL, family, "disk.svctm", "Average Service Time", "ms per operation", 2007, update_every, RRDSET_TYPE_LINE);
 594                     st->isdetail = 1;
 595
 596                     rrddim_add(st, "svctm", NULL, 1, 1, RRDDIM_ABSOLUTE);
 597                 }
 598                 else rrdset_next(st);
 599
 600                 rrddim_set(st, "svctm", ((reads - last_reads) + (writes - last_writes)) ? (busy_ms - last_busy_ms) / ((reads - last_reads) + (writes - last_writes)) : 0);
 601                 rrdset_done(st);
 602             }
 603         }
 604     }
 605
 606     return 0;
 607 }