src/proc_diskstats.c

   1 #ifdef HAVE_CONFIG_H
   2 #include <config.h>
   3 #endif
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <fcntl.h>
  10
  11 #include "common.h"
  12 #include "log.h"
  13 #include "appconfig.h"
  14 #include "procfile.h"
  15 #include "rrd.h"
  16 #include "plugin_proc.h"
  17
  18 #include "proc_self_mountinfo.h"
  19
  20 #define RRD_TYPE_DISK "disk"
  21
  22 struct disk {
  23         unsigned long major;
  24         unsigned long minor;
  25         int partition_id;       // -1 = this is not a partition
  26         char *family;
  27         struct disk *next;
  28 } *disk_root = NULL;
  29
  30 struct disk *get_disk(unsigned long major, unsigned long minor) {
  31         static char path_find_block_device_partition[FILENAME_MAX + 1] = "";
  32         static struct mountinfo *mountinfo_root = NULL;
  33         struct disk *d;
  34
  35         // search for it in our RAM list.
  36         // this is sequential, but since we just walk through
  37         // and the number of disks / partitions in a system
  38         // should not be that many, it should be acceptable
  39         for(d = disk_root; d ; d = d->next)
  40                 if(unlikely(d->major == major && d->minor == minor))
  41                         break;
  42
  43         // if we found it, return it
  44         if(likely(d))
  45                 return d;
  46
  47         if(unlikely(!path_find_block_device_partition[0])) {
  48                 char filename[FILENAME_MAX + 1];
  49                 snprintf(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/dev/block/%lu:%lu/partition");
  50                 snprintf(path_find_block_device_partition, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get block device partition", filename));
  51         }
  52
  53         // not found
  54         // create a new disk structure
  55         d = (struct disk *)malloc(sizeof(struct disk));
  56         if(!d) fatal("Cannot allocate memory for struct disk in proc_diskstats.");
  57
  58         d->major = major;
  59         d->minor = minor;
  60         d->partition_id = -1;
  61         d->next = NULL;
  62
  63         // append it to the list
  64         if(!disk_root)
  65                 disk_root = d;
  66         else {
  67                 struct disk *last;
  68                 for(last = disk_root; last->next ;last = last->next);
  69                 last->next = d;
  70         }
  71
  72         // find if it is a partition
  73         // by reading /sys/dev/block/MAJOR:MINOR/partition
  74         char buffer[FILENAME_MAX + 1];
  75         snprintf(buffer, FILENAME_MAX, path_find_block_device_partition, major, minor);
  76
  77         int fd = open(buffer, O_RDONLY, 0666);
  78         if(likely(fd != -1)) {
  79                 // we opened it
  80                 int bytes = read(fd, buffer, FILENAME_MAX);
  81                 close(fd);
  82
  83                 if(bytes > 0)
  84                         d->partition_id = strtoul(buffer, NULL, 10);
  85         }
  86         // if the /partition file does not exist, it is a disk, not a partition
  87
  88         // ------------------------------------------------------------------------
  89         // check if we can find its mount point
  90
  91         // mountinfo_find() can be called with NULL mountinfo_root
  92         struct mountinfo *mi = mountinfo_find(mountinfo_root, d->major, d->minor);
  93         if(unlikely(!mi)) {
  94                 // mountinfo_free() can be called with NULL mountinfo_root
  95                 mountinfo_free(mountinfo_root);
  96
  97                 // re-read mountinfo in case something changed
  98                 mountinfo_root = mountinfo_read();
  99
 100                 // search again for this disk
 101                 mi = mountinfo_find(mountinfo_root, d->major, d->minor);
 102         }
 103
 104         if(mi)
 105                 d->family = strdup(mi->mount_point);
 106                 // no need to check for NULL
 107         else
 108                 d->family = NULL;
 109
 110         return d;
 111 }
 112
 113 int do_proc_diskstats(int update_every, unsigned long long dt) {
 114         static procfile *ff = NULL;
 115         static char path_to_get_hw_sector_size[FILENAME_MAX + 1] = "";
 116         static int enable_new_disks = -1;
 117         static int do_io = -1, do_ops = -1, do_mops = -1, do_iotime = -1, do_qops = -1, do_util = -1, do_backlog = -1;
 118
 119         if(enable_new_disks == -1)      enable_new_disks = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "enable new disks detected at runtime", CONFIG_ONDEMAND_ONDEMAND);
 120
 121         if(do_io == -1)         do_io           = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "bandwidth for all disks", CONFIG_ONDEMAND_ONDEMAND);
 122         if(do_ops == -1)        do_ops          = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "operations for all disks", CONFIG_ONDEMAND_ONDEMAND);
 123         if(do_mops == -1)       do_mops         = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "merged operations for all disks", CONFIG_ONDEMAND_ONDEMAND);
 124         if(do_iotime == -1)     do_iotime       = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "i/o time for all disks", CONFIG_ONDEMAND_ONDEMAND);
 125         if(do_qops == -1)       do_qops         = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "queued operations for all disks", CONFIG_ONDEMAND_ONDEMAND);
 126         if(do_util == -1)       do_util         = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "utilization percentage for all disks", CONFIG_ONDEMAND_ONDEMAND);
 127         if(do_backlog == -1)do_backlog  = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "backlog for all disks", CONFIG_ONDEMAND_ONDEMAND);
 128
 129         if(!ff) {
 130                 char filename[FILENAME_MAX + 1];
 131                 snprintf(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/diskstats");
 132                 ff = procfile_open(config_get("plugin:proc:/proc/diskstats", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
 133         }
 134         if(!ff) return 1;
 135
 136         if(!path_to_get_hw_sector_size[0]) {
 137                 char filename[FILENAME_MAX + 1];
 138                 snprintf(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/sys/block/%s/queue/hw_sector_size");
 139                 snprintf(path_to_get_hw_sector_size, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get h/w sector size", filename));
 140         }
 141
 142         ff = procfile_readall(ff);
 143         if(!ff) return 0; // we return 0, so that we will retry to open it next time
 144
 145         uint32_t lines = procfile_lines(ff), l;
 146         uint32_t words;
 147
 148         for(l = 0; l < lines ;l++) {
 149                 char *disk;
 150                 unsigned long long      major = 0, minor = 0,
 151                                                         reads = 0,  mreads = 0,  readsectors = 0,  readms = 0,
 152                                                         writes = 0, mwrites = 0, writesectors = 0, writems = 0,
 153                                                         queued_ios = 0, busy_ms = 0, backlog_ms = 0;
 154
 155                 unsigned long long      last_reads = 0,  last_readsectors = 0,  last_readms = 0,
 156                                                         last_writes = 0, last_writesectors = 0, last_writems = 0,
 157                                                         last_busy_ms = 0;
 158
 159                 words = procfile_linewords(ff, l);
 160                 if(words < 14) continue;
 161
 162                 major                   = strtoull(procfile_lineword(ff, l, 0), NULL, 10);
 163                 minor                   = strtoull(procfile_lineword(ff, l, 1), NULL, 10);
 164                 disk                    = procfile_lineword(ff, l, 2);
 165
 166                 // # of reads completed # of writes completed
 167                 // This is the total number of reads or writes completed successfully.
 168                 reads                   = strtoull(procfile_lineword(ff, l, 3), NULL, 10);      // rd_ios
 169                 writes                  = strtoull(procfile_lineword(ff, l, 7), NULL, 10);      // wr_ios
 170
 171                 // # of reads merged # of writes merged
 172                 // Reads and writes which are adjacent to each other may be merged for
 173             // efficiency.  Thus two 4K reads may become one 8K read before it is
 174             // ultimately handed to the disk, and so it will be counted (and queued)
 175                 mreads                  = strtoull(procfile_lineword(ff, l, 4), NULL, 10);      // rd_merges_or_rd_sec
 176                 mwrites                 = strtoull(procfile_lineword(ff, l, 8), NULL, 10);      // wr_merges
 177
 178                 // # of sectors read # of sectors written
 179                 // This is the total number of sectors read or written successfully.
 180                 readsectors     = strtoull(procfile_lineword(ff, l, 5), NULL, 10);      // rd_sec_or_wr_ios
 181                 writesectors    = strtoull(procfile_lineword(ff, l, 9), NULL, 10);      // wr_sec
 182
 183                 // # of milliseconds spent reading # of milliseconds spent writing
 184                 // This is the total number of milliseconds spent by all reads or writes (as
 185                 // measured from __make_request() to end_that_request_last()).
 186                 readms                  = strtoull(procfile_lineword(ff, l, 6), NULL, 10);      // rd_ticks_or_wr_sec
 187                 writems                 = strtoull(procfile_lineword(ff, l, 10), NULL, 10);     // wr_ticks
 188
 189                 // # of I/Os currently in progress
 190                 // The only field that should go to zero. Incremented as requests are
 191                 // given to appropriate struct request_queue and decremented as they finish.
 192                 queued_ios              = strtoull(procfile_lineword(ff, l, 11), NULL, 10);     // ios_pgr
 193
 194                 // # of milliseconds spent doing I/Os
 195                 // This field increases so long as field queued_ios is nonzero.
 196                 busy_ms                 = strtoull(procfile_lineword(ff, l, 12), NULL, 10);     // tot_ticks
 197
 198                 // weighted # of milliseconds spent doing I/Os
 199                 // This field is incremented at each I/O start, I/O completion, I/O
 200                 // merge, or read of these stats by the number of I/Os in progress
 201                 // (field queued_ios) times the number of milliseconds spent doing I/O since the
 202                 // last update of this field.  This can provide an easy measure of both
 203                 // I/O completion time and the backlog that may be accumulating.
 204                 backlog_ms              = strtoull(procfile_lineword(ff, l, 13), NULL, 10);     // rq_ticks
 205
 206                 int def_enabled = 0;
 207
 208                 // remove slashes from disk names
 209                 char *s;
 210                 for(s = disk; *s ;s++) if(*s == '/') *s = '_';
 211
 212                 struct disk *d = get_disk(major, minor);
 213                 if(d->partition_id == -1)
 214                         def_enabled = enable_new_disks;
 215                 else
 216                         def_enabled = 0;
 217
 218                 char *family = d->family;
 219                 if(!family) family = disk;
 220
 221 /*
 222                 switch(major) {
 223                         case 9: // MDs
 224                         case 43: // network block
 225                         case 144: // nfs
 226                         case 145: // nfs
 227                         case 146: // nfs
 228                         case 199: // veritas
 229                         case 201: // veritas
 230                         case 251: // dm
 231                         case 253: // virtio
 232                                 def_enabled = enable_new_disks;
 233                                 break;
 234
 235                         case 48: // RAID
 236                         case 49: // RAID
 237                         case 50: // RAID
 238                         case 51: // RAID
 239                         case 52: // RAID
 240                         case 53: // RAID
 241                         case 54: // RAID
 242                         case 55: // RAID
 243                         case 112: // RAID
 244                         case 136: // RAID
 245                         case 137: // RAID
 246                         case 138: // RAID
 247                         case 139: // RAID
 248                         case 140: // RAID
 249                         case 141: // RAID
 250                         case 142: // RAID
 251                         case 143: // RAID
 252                         case 179: // MMC
 253                         case 180: // USB
 254                                 if(minor % 8) def_enabled = 0; // partitions
 255                                 else def_enabled = enable_new_disks;
 256                                 break;
 257
 258                         case 8: // scsi disks
 259                         case 65: // scsi disks
 260                         case 66: // scsi disks
 261                         case 67: // scsi disks
 262                         case 68: // scsi disks
 263                         case 69: // scsi disks
 264                         case 70: // scsi disks
 265                         case 71: // scsi disks
 266                         case 72: // scsi disks
 267                         case 73: // scsi disks
 268                         case 74: // scsi disks
 269                         case 75: // scsi disks
 270                         case 76: // scsi disks
 271                         case 77: // scsi disks
 272                         case 78: // scsi disks
 273                         case 79: // scsi disks
 274                         case 80: // i2o
 275                         case 81: // i2o
 276                         case 82: // i2o
 277                         case 83: // i2o
 278                         case 84: // i2o
 279                         case 85: // i2o
 280                         case 86: // i2o
 281                         case 87: // i2o
 282                         case 101: // hyperdisk
 283                         case 102: // compressed
 284                         case 104: // scsi
 285                         case 105: // scsi
 286                         case 106: // scsi
 287                         case 107: // scsi
 288                         case 108: // scsi
 289                         case 109: // scsi
 290                         case 110: // scsi
 291                         case 111: // scsi
 292                         case 114: // bios raid
 293                         case 116: // ram board
 294                         case 128: // scsi
 295                         case 129: // scsi
 296                         case 130: // scsi
 297                         case 131: // scsi
 298                         case 132: // scsi
 299                         case 133: // scsi
 300                         case 134: // scsi
 301                         case 135: // scsi
 302                         case 153: // raid
 303                         case 202: // xen
 304                         case 254: // virtio3
 305                         case 256: // flash
 306                         case 257: // flash
 307                         case 259: // nvme0n1 issue #119
 308                                 if(minor % 16) def_enabled = 0; // partitions
 309                                 else def_enabled = enable_new_disks;
 310                                 break;
 311
 312                         case 160: // raid
 313                         case 161: // raid
 314                                 if(minor % 32) def_enabled = 0; // partitions
 315                                 else def_enabled = enable_new_disks;
 316                                 break;
 317
 318                         case 3: // ide
 319                         case 13: // 8bit ide
 320                         case 22: // ide
 321                         case 33: // ide
 322                         case 34: // ide
 323                         case 56: // ide
 324                         case 57: // ide
 325                         case 88: // ide
 326                         case 89: // ide
 327                         case 90: // ide
 328                         case 91: // ide
 329                                 if(minor % 64) def_enabled = 0; // partitions
 330                                 else def_enabled = enable_new_disks;
 331                                 break;
 332
 333                         case 252: // zram
 334                                 def_enabled = 0;
 335                                 break;
 336
 337                         default:
 338                                 def_enabled = 0;
 339                                 break;
 340                 }
 341 */
 342
 343                 int ddo_io = do_io, ddo_ops = do_ops, ddo_mops = do_mops, ddo_iotime = do_iotime, ddo_qops = do_qops, ddo_util = do_util, ddo_backlog = do_backlog;
 344
 345                 // check which charts are enabled for this disk
 346                 {
 347                         char var_name[4096 + 1];
 348                         snprintf(var_name, 4096, "plugin:proc:/proc/diskstats:%s", disk);
 349                         def_enabled = config_get_boolean_ondemand(var_name, "enabled", def_enabled);
 350                         if(def_enabled == CONFIG_ONDEMAND_NO) continue;
 351                         if(def_enabled == CONFIG_ONDEMAND_ONDEMAND && !reads && !writes) continue;
 352
 353
 354                         ddo_io          = config_get_boolean_ondemand(var_name, "bandwidth", ddo_io);
 355                         ddo_ops         = config_get_boolean_ondemand(var_name, "operations", ddo_ops);
 356                         ddo_mops        = config_get_boolean_ondemand(var_name, "merged operations", ddo_mops);
 357                         ddo_iotime      = config_get_boolean_ondemand(var_name, "i/o time", ddo_iotime);
 358                         ddo_qops        = config_get_boolean_ondemand(var_name, "queued operations", ddo_qops);
 359                         ddo_util        = config_get_boolean_ondemand(var_name, "utilization percentage", ddo_util);
 360                         ddo_backlog = config_get_boolean_ondemand(var_name, "backlog", ddo_backlog);
 361
 362                         // by default, do not add charts that do not have values
 363                         if(ddo_io == CONFIG_ONDEMAND_ONDEMAND && !reads && !writes) ddo_io = 0;
 364                         if(ddo_mops == CONFIG_ONDEMAND_ONDEMAND && mreads == 0 && mwrites == 0) ddo_mops = 0;
 365                         if(ddo_iotime == CONFIG_ONDEMAND_ONDEMAND && readms == 0 && writems == 0) ddo_iotime = 0;
 366                         if(ddo_util == CONFIG_ONDEMAND_ONDEMAND && busy_ms == 0) ddo_util = 0;
 367                         if(ddo_backlog == CONFIG_ONDEMAND_ONDEMAND && backlog_ms == 0) ddo_backlog = 0;
 368                         if(ddo_qops == CONFIG_ONDEMAND_ONDEMAND && backlog_ms == 0) ddo_qops = 0;
 369
 370                         // for absolute values, we need to switch the setting to 'yes'
 371                         // to allow it refresh from now on
 372                         if(ddo_qops == CONFIG_ONDEMAND_ONDEMAND) config_set(var_name, "queued operations", "yes");
 373                 }
 374
 375                 RRDSET *st;
 376
 377                 // --------------------------------------------------------------------
 378
 379                 int sector_size = 512;
 380                 if(ddo_io) {
 381                         st = rrdset_find_bytype(RRD_TYPE_DISK, disk);
 382                         if(!st) {
 383                                 char tf[FILENAME_MAX + 1], *t;
 384                                 char ssfilename[FILENAME_MAX + 1];
 385
 386                                 strncpy(tf, disk, FILENAME_MAX);
 387                                 tf[FILENAME_MAX] = '\0';
 388
 389                                 // replace all / with !
 390                                 while((t = strchr(tf, '/'))) *t = '!';
 391
 392                                 snprintf(ssfilename, FILENAME_MAX, path_to_get_hw_sector_size, tf);
 393                                 FILE *fpss = fopen(ssfilename, "r");
 394                                 if(fpss) {
 395                                         char ssbuffer[1025];
 396                                         char *tmp = fgets(ssbuffer, 1024, fpss);
 397
 398                                         if(tmp) {
 399                                                 sector_size = atoi(tmp);
 400                                                 if(sector_size <= 0) {
 401                                                         error("Invalid sector size %d for device %s in %s. Assuming 512.", sector_size, disk, ssfilename);
 402                                                         sector_size = 512;
 403                                                 }
 404                                         }
 405                                         else error("Cannot read data for sector size for device %s from %s. Assuming 512.", disk, ssfilename);
 406
 407                                         fclose(fpss);
 408                                 }
 409                                 else error("Cannot read sector size for device %s from %s. Assuming 512.", disk, ssfilename);
 410
 411                                 st = rrdset_create(RRD_TYPE_DISK, disk, NULL, family, "disk.io", "Disk I/O Bandwidth", "kilobytes/s", 2000, update_every, RRDSET_TYPE_AREA);
 412
 413                                 rrddim_add(st, "reads", NULL, sector_size, 1024, RRDDIM_INCREMENTAL);
 414                                 rrddim_add(st, "writes", NULL, sector_size * -1, 1024, RRDDIM_INCREMENTAL);
 415                         }
 416                         else rrdset_next_usec(st, dt);
 417
 418                         last_readsectors  = rrddim_set(st, "reads", readsectors);
 419                         last_writesectors = rrddim_set(st, "writes", writesectors);
 420                         rrdset_done(st);
 421                 }
 422
 423                 // --------------------------------------------------------------------
 424
 425                 if(ddo_ops) {
 426                         st = rrdset_find_bytype("disk_ops", disk);
 427                         if(!st) {
 428                                 st = rrdset_create("disk_ops", disk, NULL, family, "disk.ops", "Disk Completed I/O Operations", "operations/s", 2001, update_every, RRDSET_TYPE_LINE);
 429                                 st->isdetail = 1;
 430
 431                                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 432                                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 433                         }
 434                         else rrdset_next_usec(st, dt);
 435
 436                         last_reads  = rrddim_set(st, "reads", reads);
 437                         last_writes = rrddim_set(st, "writes", writes);
 438                         rrdset_done(st);
 439                 }
 440
 441                 // --------------------------------------------------------------------
 442
 443                 if(ddo_qops) {
 444                         st = rrdset_find_bytype("disk_qops", disk);
 445                         if(!st) {
 446                                 st = rrdset_create("disk_qops", disk, NULL, family, "disk.qops", "Disk Current I/O Operations", "operations", 2002, update_every, RRDSET_TYPE_LINE);
 447                                 st->isdetail = 1;
 448
 449                                 rrddim_add(st, "operations", NULL, 1, 1, RRDDIM_ABSOLUTE);
 450                         }
 451                         else rrdset_next_usec(st, dt);
 452
 453                         rrddim_set(st, "operations", queued_ios);
 454                         rrdset_done(st);
 455                 }
 456
 457                 // --------------------------------------------------------------------
 458
 459                 if(ddo_backlog) {
 460                         st = rrdset_find_bytype("disk_backlog", disk);
 461                         if(!st) {
 462                                 st = rrdset_create("disk_backlog", disk, NULL, family, "disk.backlog", "Disk Backlog", "backlog (ms)", 2003, update_every, RRDSET_TYPE_AREA);
 463                                 st->isdetail = 1;
 464
 465                                 rrddim_add(st, "backlog", NULL, 1, 10, RRDDIM_INCREMENTAL);
 466                         }
 467                         else rrdset_next_usec(st, dt);
 468
 469                         rrddim_set(st, "backlog", backlog_ms);
 470                         rrdset_done(st);
 471                 }
 472
 473                 // --------------------------------------------------------------------
 474
 475                 if(ddo_util) {
 476                         st = rrdset_find_bytype("disk_util", disk);
 477                         if(!st) {
 478                                 st = rrdset_create("disk_util", disk, NULL, family, "disk.util", "Disk Utilization Time", "% of time working", 2004, update_every, RRDSET_TYPE_AREA);
 479                                 st->isdetail = 1;
 480
 481                                 rrddim_add(st, "utilization", NULL, 1, 10, RRDDIM_INCREMENTAL);
 482                         }
 483                         else rrdset_next_usec(st, dt);
 484
 485                         last_busy_ms = rrddim_set(st, "utilization", busy_ms);
 486                         rrdset_done(st);
 487                 }
 488
 489                 // --------------------------------------------------------------------
 490
 491                 if(ddo_mops) {
 492                         st = rrdset_find_bytype("disk_mops", disk);
 493                         if(!st) {
 494                                 st = rrdset_create("disk_mops", disk, NULL, family, "disk.mops", "Disk Merged Operations", "merged operations/s", 2021, update_every, RRDSET_TYPE_LINE);
 495                                 st->isdetail = 1;
 496
 497                                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 498                                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 499                         }
 500                         else rrdset_next_usec(st, dt);
 501
 502                         rrddim_set(st, "reads", mreads);
 503                         rrddim_set(st, "writes", mwrites);
 504                         rrdset_done(st);
 505                 }
 506
 507                 // --------------------------------------------------------------------
 508
 509                 if(ddo_iotime) {
 510                         st = rrdset_find_bytype("disk_iotime", disk);
 511                         if(!st) {
 512                                 st = rrdset_create("disk_iotime", disk, NULL, family, "disk.iotime", "Disk Total I/O Time", "milliseconds/s", 2022, update_every, RRDSET_TYPE_LINE);
 513                                 st->isdetail = 1;
 514
 515                                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 516                                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 517                         }
 518                         else rrdset_next_usec(st, dt);
 519
 520                         last_readms  = rrddim_set(st, "reads", readms);
 521                         last_writems = rrddim_set(st, "writes", writems);
 522                         rrdset_done(st);
 523                 }
 524
 525                 // --------------------------------------------------------------------
 526                 // calculate differential charts
 527                 // only if this is not the first time we run
 528
 529                 if(dt) {
 530                         if(ddo_iotime && ddo_ops) {
 531                                 st = rrdset_find_bytype("disk_await", disk);
 532                                 if(!st) {
 533                                         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);
 534                                         st->isdetail = 1;
 535
 536                                         rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_ABSOLUTE);
 537                                         rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_ABSOLUTE);
 538                                 }
 539                                 else rrdset_next_usec(st, dt);
 540
 541                                 rrddim_set(st, "reads", (reads - last_reads) ? (readms - last_readms) / (reads - last_reads) : 0);
 542                                 rrddim_set(st, "writes", (writes - last_writes) ? (writems - last_writems) / (writes - last_writes) : 0);
 543                                 rrdset_done(st);
 544                         }
 545
 546                         if(ddo_io && ddo_ops) {
 547                                 st = rrdset_find_bytype("disk_avgsz", disk);
 548                                 if(!st) {
 549                                         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);
 550                                         st->isdetail = 1;
 551
 552                                         rrddim_add(st, "reads", NULL, sector_size, 1024, RRDDIM_ABSOLUTE);
 553                                         rrddim_add(st, "writes", NULL, -sector_size, 1024, RRDDIM_ABSOLUTE);
 554                                 }
 555                                 else rrdset_next_usec(st, dt);
 556
 557                                 rrddim_set(st, "reads", (reads - last_reads) ? (readsectors - last_readsectors) / (reads - last_reads) : 0);
 558                                 rrddim_set(st, "writes", (writes - last_writes) ? (writesectors - last_writesectors) / (writes - last_writes) : 0);
 559                                 rrdset_done(st);
 560                         }
 561
 562                         if(ddo_util && ddo_ops) {
 563                                 st = rrdset_find_bytype("disk_svctm", disk);
 564                                 if(!st) {
 565                                         st = rrdset_create("disk_svctm", disk, NULL, family, "disk.svctm", "Average Service Time", "ms per operation", 2007, update_every, RRDSET_TYPE_LINE);
 566                                         st->isdetail = 1;
 567
 568                                         rrddim_add(st, "svctm", NULL, 1, 1, RRDDIM_ABSOLUTE);
 569                                 }
 570                                 else rrdset_next_usec(st, dt);
 571
 572                                 rrddim_set(st, "svctm", ((reads - last_reads) + (writes - last_writes)) ? (busy_ms - last_busy_ms) / ((reads - last_reads) + (writes - last_writes)) : 0);
 573                                 rrdset_done(st);
 574                         }
 575                 }
 576         }
 577
 578         return 0;
 579 }