Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, We try to use DRBD in some reason. After some tests using tiobench like DRBD's performance page, we found the write rate is too low, almost 1/2 in Sequential Writes, 1/4 in Random Writes. We use two HP-DL140, with 2.8GHz P4 CPU*2 (with HyperThreads), 4GB memory and 2 SATA Maxtor hard-disk (we just use one of the two on each machine), and got these results: 1. Sequential Writes Identifier File Size Blk Size Num Thr Rate Maximum CPU% Avg Latency Max Latency Lat% >2s Lat% >10s CPU Eff 2.6.15.4 6144 4096 4 35.19 112.000% 1.004 16665.66 0.00515 0.00000 31 2.6.15.4-dis 6144 4096 4 17.58 54.070% 1.881 283191.21 0.01303 0.00134 33 2.6.15.4-prot-c 6144 4096 4 19.21 65.180% 1.607 683948.76 0.00648 0.00134 29 2.6.15.4 6144 4096 8 34.13 221.600% 1.905 45493.9 0.01908 0.00019 15 2.6.15.4-dis 6144 4096 8 18.48 115.400% 3.204 348416.72 0.04895 0.00178 16 2.6.15.4-prot-c 6144 4096 8 19.18 149.900% 2.952 575454.06 0.03472 0.00248 13 2.6.15.4 6144 4096 16 35.29 461.600% 3.176 40471.59 0.08113 0.00051 8 2.6.15.4-dis 6144 4096 16 17.40 241.100% 6.184 354021.31 0.07319 0.01087 7 2.6.15.4-prot-c 6144 4096 16 18.78 332.300% 5.087 635343.88 0.05341 0.00826 6 2. Random Writes Identifier File Size Blk Size Num Thr Rate Maximum CPU% Avg Latency Max Latency Lat% >2s Lat% >10s CPU Eff 2.6.15.4 6144 4096 4 0.59 1.032% 10.097 3155.68 0.00000 0.00000 57 2.6.15.4-dis 6144 4096 4 0.12 0.454% 6.362 388.50 0.00000 0.00000 26 2.6.15.4-prot-c 6144 4096 4 0.15 0.583% 6.715 436.39 0.00000 0.00000 26 2.6.15.4 6144 4096 8 0.59 2.596% 1.400 437.01 0.00000 0.00000 23 2.6.15.4-dis 6144 4096 8 0.13 2.661% 0.072 32.24 0.00000 0.00000 5 2.6.15.4-prot-c 6144 4096 8 0.15 1.541% 7.065 493.70 0.00000 0.00000 10 2.6.15.4 6144 4096 16 0.65 4.094% 0.049 0.26 0.00000 0.00000 16 2.6.15.4-dis 6144 4096 16 0.13 3.657% 1.359 277.98 0.00000 0.00000 3 2.6.15.4-prot-c 6144 4096 16 0.17 5.794% 2.486 494.66 0.00000 0.00000 3 We care the 'rate' field more, and found that after using DRBD, either connect or disconnect, the 'rate' took down from [35] to [17], and [0.6] to [0.15] ... so we cannot REPLAY the results on DRBD's page... very confused. Who can tell me the possible reason, thanks very much!