Hi All, I am trying to performance test my device mapper for zoned devices; I am trying to repliate the 80 - 20 principle for I/O. I understand that this can be done in the following three ways using fio. a) zoned - simplest of the three : zoned:80/20:20/80 However, this restricts the first 20% space to get 80% of the I/O and vice versa. The good thing though is that zoned distribution can be used to achieve a russian doll effect. b) zipf:1.2 I used fio-genzipf to visualize the random I/O pattern: fio-genzipf -t zipf -i 1.2 -b 4096 -g 100GiB Generating Zipf distribution with 1.200000 input and 100 GiB size and 4096 block_size. Rows Hits % Sum % # Hits Size ----------------------------------------------------------------------- Top 5.00% 93.31% 93.31% 24459924 93.31G |-> 10.00% 1.34% 94.65% 352314 1.34G |-> 15.00% 0.77% 95.42% 201010 785.20M |-> 20.00% 0.51% 95.92% 132667 518.23M |-> 25.00% 0.47% 96.39% 122386 478.07M |-> 30.00% 0.34% 96.73% 89402 349.23M |-> 35.00% 0.23% 96.97% 61193 239.04M |-> 40.00% 0.23% 97.20% 61193 239.04M |-> 45.00% 0.23% 97.43% 61193 239.04M |-> 50.00% 0.23% 97.67% 61193 239.04M |-> 55.00% 0.23% 97.90% 61193 239.04M |-> 60.00% 0.23% 98.13% 61193 239.04M |-> 65.00% 0.23% 98.37% 61193 239.04M |-> 70.00% 0.23% 98.60% 61193 239.04M |-> 75.00% 0.23% 98.83% 61193 239.04M |-> 80.00% 0.23% 99.07% 61193 239.04M |-> 85.00% 0.23% 99.30% 61193 239.04M |-> 90.00% 0.23% 99.53% 61193 239.04M |-> 95.00% 0.23% 99.77% 61193 239.04M |-> 100.00% 0.23% 100.00% 61188 239.02M ----------------------------------------------------------------------- Total 26214400 I need help with this interpretation. Does this mean that 5% of the LBAs get 93.31% hits, the next 5% gets 1.34% etc. It seems that way to me. However, this does not have the Russian doll effect - ie the 5% of the rest of 95% does not get the rest of ~93% I/O. Is the 5% range - scattered over the disk or is this similar to zoned distribution, in that a contiguous space gets the 93% I/O. In that case, this is similar to zoned distribution, right? c) pareto - fio-genzipf -t pareto -i 0.04 -b 4096 -g 100GiB Generating Pareto distribution with 0.040000 input and 100 GiB size and 4096 block_size. Rows Hits % Sum % # Hits Size ----------------------------------------------------------------------- Top 5.00% 93.04% 93.04% 24388831 93.04G |-> 10.00% 0.99% 94.02% 259143 1012.28M |-> 15.00% 0.60% 94.63% 158285 618.30M |-> 20.00% 0.59% 95.22% 154826 604.79M |-> 25.00% 0.35% 95.57% 92138 359.91M |-> 30.00% 0.30% 95.87% 77413 302.39M |-> 35.00% 0.30% 96.16% 77413 302.39M |-> 40.00% 0.30% 96.46% 77413 302.39M |-> 45.00% 0.30% 96.75% 77413 302.39M |-> 50.00% 0.30% 97.05% 77413 302.39M |-> 55.00% 0.30% 97.34% 77413 302.39M |-> 60.00% 0.30% 97.64% 77413 302.39M |-> 65.00% 0.30% 97.93% 77413 302.39M |-> 70.00% 0.30% 98.23% 77413 302.39M |-> 75.00% 0.30% 98.52% 77413 302.39M |-> 80.00% 0.30% 98.82% 77413 302.39M |-> 85.00% 0.30% 99.11% 77413 302.39M |-> 90.00% 0.30% 99.41% 77413 302.39M |-> 95.00% 0.30% 99.70% 77413 302.39M |-> 100.00% 0.30% 100.00% 77395 302.32M ----------------------------------------------------------------------- Total 26214400 This to me looks pretty much similar to the zipf distribution above. Is this understanding correct ? Or am I missing something here? Thanks a lot for your help!
