Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, I ran some drbd performance tests with 'tiobench': tiobench.pl --identifier drbd-connected --size 5000 --numruns 1 --dir /secroot --block 4096 --threads 4 noticed the huge max latency numbers with Sequential Writes: Unit information ================ File size = megabytes Blk Size = bytes Rate = megabytes per second CPU% = percentage of CPU used during the test Latency = milliseconds Lat% = percent of requests that took longer than X seconds CPU Eff = Rate divided by CPU% - throughput per cpu load Identifier File Size Blk Size Num Thr Rate Maximum CPU% Avg Latency Max Latency Lat% >2s Lat% >10s CPU Eff Raw-device 5000 4096 4 31.24 26.80% 0.364 5635.06 0.00242 0.00000 117 Drbd-disconnected 5000 4096 4 33.18 26.29% 0.319 110394.58 0.00190 0.00016 126 Drbd-connected 5000 4096 4 20.88 50.18% 0.457 135712.09 0.00110 0.00008 42 My lab setting: * Two Linux nodes on 2.6.10_mvlcge401-pc_target-x86_pentium3-P3SMP. * Dual-core Intel Xeon 2GHz CPU, 4GB Memory, 1Gbits/s network interface. * 5.7GB partition on SCSI disk, ext2 file system with the "-T largefile4" option. * DRBD version is 0.7.11, rate=100M; protocal C; sndbuf-size 1024k. I don't believe the disk (~50MB/s) or network may be the factors here. You can see the big number jump even with the DRBD disconnected mode. Any help on analyzing/identifying the problem will be greatly appreciated. Weilin -------------- next part -------------- A non-text attachment was scrubbed... Name: wgong.vcf Type: text/x-vcard Size: 126 bytes Desc: not available URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20070105/e09d11f1/attachment.vcf>