@longli I would like your assessment of the changes that we've made here to get back to expected performance. I know we are not getting the same results on NVMe devices with 16.04 and 18.04 and I'm wondering if there's something substantially different with the 4.15 kernel in use on 16.04 that prevents us from making the same changes that we did with 4.18 to get better performance.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-azure in Ubuntu. https://bugs.launchpad.net/bugs/1828248 Title: [linux-azure] Storage performance drop on RAID Status in linux-azure package in Ubuntu: New Status in linux-azure source package in Xenial: Fix Committed Bug description: In Azure, FIO 4k tests are showing performance drops on latest proposed 4.15.0 linux-azure kernels - from 52K IOPS to ~38K IOPS (max value reached on both sequential and random read tests). The setup used is 12 disks in RAID0. The affected kernels are: Ubuntu 14.04 + 4.15.0-1043 Ubuntu 16.04 + 4.15.0-1044 Previous kernel versions had reached max IOPS, ~52K IOPS on both read tests (e.g. 16.04 + 4.15.0-1043 kernel). Right now, it seems like the issue is in the diff from 1043 kernel on trusty vs 1044 kernel on xenial. The 52K IOPS is expected at qdepth=256. The repro cmd (as ran by the automation) is this: fio --size=1023G --direct=1 --ioengine=libaio --filename=/dev/md0 --overwrite=1 --readwrite=randread --bs=4K --runtime=300 --iodepth=32 --numjob=8 --output-format=json --output=/root/FIOLog/jsonLog/fio-result-randread-4K-256td.json --name='repro' To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-azure/+bug/1828248/+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
