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compcache - zramIOzone.wiki

Introduction

IOzone is a filesystem benchmark tool. It was used to generate variety of filesystem (ext4) workload over zram devices.

Details

Common configuration for ram and zram disks case

  • Tests were run natively (not in a VM)
  • Host OS: Fedora 11 x86_64
  • Host configuration: CPU: Intel Core 2 Duo (T9600, 2.8GHz), RAM: 4G
  • Boot into runlevel 3 and turn off crond, atd, cpuspeed

ram disk case

  • Create 3G ram disk using ramdisk_size boot param
  • mkfs.ext4 /dev/ram0
  • mount /dev/ram0 /mnt/other

zram disk case

  • Create 3G zram disk using zramconfig
  • mkfs.ext4 /dev/zram0
  • mount /dev/zram0 /mnt/other

IOzone command

iozone -a -B -n 1G -g 2G -G -R -b iozone.xls -M -+u

-a: Automatic mode. -B: Use mmap() files. -n: Minimum file size. -g: Maximum file size. -G Use msync(MS_SYNC) on mmap files -R: Generate excel output. -b: Excel output filename. -M: uname() output in results. -+u: Enable CPU stats.

In parallel, run: watch -n 1 'echo 1 > /proc/sys/vm/drop_caches' This will drop/free pagecache every 1 second. This forces most of the I/O to actually go to disk.

Results

Actual numbers do not matter since the effect of pagecache make R/W appear faster than reality. For more accurate performance numbers, refer zramperf. This IOzone test was done primarily to stress zram code and not to measure performance.

Each test was run 5 times and no error was observed.

ramdisk case

``` Machine = Linux vflare 2.6.34 #1 SMP Wed May 19 13:04:50 IST 2010 x86_64 x86_6 CPU utilization Resolution = 0.001 seconds. CPU utilization Resolution = 0.001 seconds. CPU utilization Excel chart enabled Command line used: /home/ngupta/opt/iozone/src/current/iozone -a -B -n 1G -g 2G -G -R -b iozone.xls -M -+u Output is in Kbytes/sec Time Resolution = 0.000001 seconds. Processor cache size set to 1024 Kbytes. Processor cache line size set to 32 bytes. File stride size set to 17 * record size. random random bkwd record stride KB reclen write rewrite read reread read write read rewrite read 1048576 64 309500 346052 741827 692543 668591 342610 943661 375120 986910 1048576 128 359506 390935 608138 870010 493423 310893 783716 391109 654727 1048576 256 389008 371681 868290 870373 641083 356326 986793 389621 825965 1048576 512 411349 346160 808808 779252 666401 403118 1093451 409388 886225 1048576 1024 434998 377833 790972 744039 538548 398744 1026594 402078 734151 1048576 2048 397826 340499 728962 698772 657706 394667 647407 397864 935239 1048576 4096 400690 354910 653682 588612 473785 376885 781584 395144 602351 1048576 8192 391729 351347 656444 561333 674144 385264 738427 388412 692058 1048576 16384 380419 383663 488296 627425 639278 381618 769378 385701 464041 2097152 64 290187 343444 656998 708405 557515 289988 701520 313568 742025 2097152 128 341624 347826 752151 743522 419107 233937 725035 366825 548462 2097152 256 381127 365021 711029 718995 533597 289949 743980 354228 526949 2097152 512 398443 362675 778044 755627 614676 334848 744319 374755 731869 2097152 1024 395428 374523 534204 675757 611516 350119 723927 374815 591226 2097152 2048 395592 375151 631266 652976 628337 374699 671840 371318 605499 2097152 4096 379787 357786 486780 599601 595327 328224 624011 353998 527587 2097152 8192 378041 359126 567922 524867 476484 356595 607510 367276 576345 2097152 16384 370599 361646 608814 598262 590169 367291 531728 363478 563297

iozone test complete. ```

zramdisk case

``` Machine = Linux vflare 2.6.34 #1 SMP Wed May 19 13:04:50 IST 2010 x86_64 x86_6 CPU utilization Resolution = 0.001 seconds. CPU utilization Resolution = 0.001 seconds. CPU utilization Excel chart enabled Command line used: /home/ngupta/opt/iozone/src/current/iozone -a -B -n 1G -g 2G -G -R -b iozone.xls -M -+u Output is in Kbytes/sec Time Resolution = 0.000001 seconds. Processor cache size set to 1024 Kbytes. Processor cache line size set to 32 bytes. File stride size set to 17 * record size. random random bkwd record stride KB reclen write rewrite read reread read write read rewrite read 1048576 64 226178 255617 479036 460596 2244167 193102 905992 230000 1111346 1048576 128 274232 230013 578938 2271981 269776 170376 2232842 221372 2251926 1048576 256 311753 251856 2285788 1180270 2244234 183105 2256977 235259 1475296 1048576 512 330645 236067 536017 962596 758183 248576 2255977 258073 2236008 1048576 1024 344364 237175 454852 2255695 1577881 249907 2240691 232577 2255987 1048576 2048 348098 233300 2145572 1237024 2123702 224368 2123672 242684 1066512 1048576 4096 348580 232020 1390494 432517 1394587 225765 1156772 223862 859950 1048576 8192 348501 230655 1247663 374442 575120 247239 804708 244736 659031 1048576 16384 339752 226126 807560 528928 630223 265362 453253 228401 971366 2097152 64 230949 219985 2235560 2304147 2266475 171366 1333621 208522 1285780 2097152 128 280088 220032 934568 745437 1920407 170593 810684 215980 370272 2097152 256 311173 218876 587314 433425 881887 186110 1748379 226138 409723 2097152 512 329355 223234 564243 2342699 364212 214951 936711 237650 1283409 2097152 1024 339664 242885 1102029 2139366 1850092 234779 810483 230460 1114067 2097152 2048 342278 236132 498602 617058 500605 226954 1060779 228319 850868 2097152 4096 344085 223445 417500 550464 386282 221147 440016 233749 410492 2097152 8192 345870 228366 543570 395759 434723 237362 527818 235590 449568 2097152 16384 341133 239329 484319 491404 520720 239360 559416 235280 434267

iozone test complete. ```

No I/O errors were observed during/after the test

Output of zram stats after the test: zramconfig /dev/zram0 --stats

DiskSize: 3145728 kB NumReads: 4990928 NumWrites: 59131245 FailedReads: 0 <----\ FailedWrites: 0 <-----\ InvalidIO: 0 <----- No errors NotifyFree: 0 ZeroPages: 12341 GoodCompress: 99 % NoCompress: 0 % PagesStored: 710862 PagesUsed: 7281 OrigDataSize: 2843448 kB ComprDataSize: 25377 kB MemUsedTotal: 29124 kB