Public bug reported: Hello, We have been running multiple tests using the md driver to build various type of RAID devices. Performances on RAID5 are particularly disappointing so we would like to know if there are any known issue with the md driver on Bionic kernels. Here are some of our results :
Test (Threads) QCT JBODQCT RAID5 (8 threads) QCT RAID10 read(1) 838 751 (-10%) 572 (-32%) read(2) 1226 1172 (-4%) 1057 (-14%) read(4) 1129 2006 (+78%) 1760 (+56%) write(1) 804 382 (-52%) 398 (-50%) write(2) 1047 175 (-83%) 667 (-36%) write(4) 883 415 (-53%) 871 (-1%) randread(1) 863 749 (-13%) 619 (-28%) randread(2) 1346 1067 (-21%) 1020 (-24%) randread(4) 1648 1785 (+8%) 1650 (=) randwrite(1) 766 287 (-63%) 391 (-50%) randwrite(2) 1044 313 (-70%) 664 (-36%) randwrite(4) 916 282 (-69%) 885 (-3%) We are preparing tests with one of the latest mainline kernel. TIA, ...Louis ** Affects: linux (Ubuntu) Importance: Undecided Status: Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1815178 Title: 18.04: Raid5 performances on kernel 4.15 are suboptimal To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1815178/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs