Hi, I was doing some experiments to test out blkio with the following setups and was unable to get the expected behavior. It will be great if someone can help me understand what might have gone wrong with my setup. Setup 1 hardware: d2.xlarge machine on aws (It has 3 * 2 TB hdd) logical volume: setup an lvm to use 2 disks out of 3 file system: xfs IO Scheduler: cfq blkio weights: test1 has weight 1000, test2 has weight 500 Now when I run the tests as given in https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt using dd (I only executed read tests on already written files) I found that both the processes were getting equal time share (blkio.time) and serviced bytes (blkio.io_service_bytes) irrespective of differential weights. Now when I modified the setup by not having lvm setup and just creating a 2TB file system out of a single hdd it worked i.e. serviced bytes were in the ratio 2 : 1 On the other hand when I tested read with fio specifically fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test2 --filename=file2 --bs=4k --iodepth=64 --size=4G --readwrite=randrw --rwmixread=100 Then also it worked even with the lvm setup. Which makes be believe that with Setup 1 it is not working due to buffered reads. (But then the same thing also worked without lvm) Setup 2 hardware: c3.xlarge machine on aws with 300GB EBS (which I believe are like SAN storage) logical volume: setup an lvm file system: xfs IO Scheduler: cfq blkio weights: test1 has weight 1000, test 2 has weight 500 Now with this setup I was not able to get it working in any of the cases i.e. with lvm, without lvm, with fio sync reads. Is it the problem with using EBS volumes? Is there way in which I can get blkio to work with Setup 1 and Setup 2? Please let me know if providing more data points might help. Regards - Himadri -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
