** Changed in: linux (Ubuntu)
       Status: In Progress => Incomplete

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1815178

Title:
  18.04: Raid performances on kernel 4.15 and newer are suboptimal when
  used on NVMe devices

Status in linux package in Ubuntu:
  Incomplete

Bug description:
  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

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1815178/+subscriptions

-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to