Hi Folks - we have some admittedly underpowered 270c in a mixed cifs/nfs environment. We are seeing a random performance issue whereby cp time is increased and the resultant nfs ops it serves drops considerably, resulting in an effective outage.
The question is when I look at the sysstat output collected during these periods a lot of time is spent checkpointing 'special files' - its been a while since I covered ontap theory so if someone could explain this in further detail it would be helpful. The now docs omit extended explanations.
Below is a sample of normal vs check pointing sysstat output.
Thanks,
Daryl
Normal
CPU NFS CIFS HTTP Total Net kB/s Disk kB/s Tape kB/s Cache Cache CP CP Disk FCP iSCSI FCP kB/s in out read write read write age hit time ty util in out 92% 1758 2 0 1760 495 2621 6404 0 0 0 41s 75% 0% - 55% 0 0 0 0 89% 2759 3 0 2762 781 6441 11140 6 0 0 22s 83% 0% - 68% 0 0 0 0 96% 2605 20 0 2625 1566 7347 12961 24 0 0 41s 78% 0% - 70% 0 0 0 0 97% 2224 3 0 2227 688 4856 8198 0 0 0 41s 84% 0% - 49% 0 0 0 0 92% 4027 2 0 4029 1860 5267 9829 12 0 0 14s 89% 0% - 72% 0 0 0 0 96% 2136 0 0 2136 535 1809 6405 17 0 0 42s 85% 0% - 64% 0 0 0 0 95% 2383 0 0 2383 642 3245 8769 0 0 0 42s 82% 0% - 67% 0 0 0 0 97% 2210 0 0 2210 595 3823 8309 1578 0 0 14s 89% 66% Tn 61% 0 0 0 0 85% 4889 0 0 4889 1881 5163 15287 7252 0 0 23s 85% 100% :s 100% 0 0 0 0 90% 2393 3 0 2396 817 10048 18018 2474 0 0 39s 89% 100% :s 70% 0 0 0 0 95% 1603 18 0 1621 913 4532 8437 4025 0 0 40s 88% 100% :v 54% 0 0 0 0 94% 2260 0 0 2260 1109 4061 8470 51 0 0 40s 82% 12% : 61% 0 0 0 0 88% 3532 3 1 3536 890 5716 11892 0 0 0 24s 83% 0% - 71% 0 0 0 0 92% 3347 2 0 3349 2197 6462 11603 20 0 0 23s 87% 0% - 68% 0 0 0 0 94% 3607 17 0 3624 1013 6285 11300 7 0 0 15s 85% 0% - 69% 0 0 0 0 95% 2359 7 0 2366 598 4574 8985 0 0 0 41s 84% 0% - 69% 0 0 0 0 94% 3981 0 0 3981 1098 4065 10324 23 0 0 39s 86% 0% - 74% 0 0 0 0 83% 3965 0 0 3965 946 4709 11296 0 0 0 39s 82% 0% - 83% 0 0 0 0 88% 3318 0 0 3318 1009 5220 11772 24 0 0 23s 83% 0% - 86% 0 0 0 0 88% 2821 0 0 2821 750 3974 9762 8 0 0 14s 79% 0% - 69% 0 0 0 0
Check Pointed
CPU NFS CIFS HTTP Total Net kB/s Disk kB/s Tape kB/s Cache Cache CP CP Disk FCP iSCSI FCP kB/s in out read write read write age hit time ty util in out 98% 1651 7 0 1658 669 2196 8671 15 0 0 49s 88% 0% - 44% 0 0 0 0 99% 567 0 0 567 176 1022 2601 3 0 0 46s 87% 0% - 41% 0 0 0 0 99% 614 0 0 614 205 1632 3408 8 0 0 1 89% 22% :n 27% 0 0 0 0 99% 929 1 0 930 252 1803 3865 237 0 0 44s 89% 100% Tn 32% 0 0 0 0 98% 463 0 0 463 385 1338 4066 1224 0 0 1 91% 100% :n 32% 0 0 0 0 98% 398 6 0 404 145 1894 5134 1787 0 0 1 81% 100% :s 34% 0 0 0 0 99% 558 0 0 558 186 1716 3675 912 0 0 50s 89% 100% :s 34% 0 0 0 0 99% 677 1 0 678 919 902 2892 587 0 0 1 87% 100% :s 33% 0 0 0 0 99% 703 1 0 704 293 1179 3173 731 0 0 52s 89% 100% :s 26% 0 0 0 0 97% 2250 17 0 2267 717 3024 10358 3462 0 0 52s 94% 100% :v 63% 0 0 0 0 98% 1032 0 0 1032 619 933 2482 81 0 0 49s 92% 11% : 33% 0 0 0 0 99% 875 1 0 876 293 2328 3818 6 0 0 44s 92% 0% - 33% 0 0 0 0 99% 325 0 0 325 116 579 1595 5 0 0 42s 91% 0% - 23% 0 0 0 0 99% 884 1 0 885 382 1613 3723 10 0 0 1 93% 38% :n 24% 0 0 0 0 98% 917 0 0 917 586 1193 3136 415 0 0 42s 88% 100% Tn 31% 0 0 0 0 99% 675 0 0 675 462 554 4040 2610 0 0 1 90% 100% :s 28% 0 0 0 0 98% 718 0 0 718 396 990 2469 355 0 0 44s 92% 100% :s 30% 0 0 0 0 99% 555 1 0 556 181 965 2101 257 0 0 1 89% 100% :s 33% 0 0 0 0 99% 824 0 0 824 391 1268 3484 877 0 0 48s 97% 100% :s 29% 0 0 0 0 97% 2119 14 0 2133 2154 2389 5898 347 0 0 45s 93% 100% :f 50% 0 0 0 0