Hello, I am not sure I understand what you are asking. VM workloads can be anything that you would want to test, unless there is a specific specification that you are looking at. In the case of having many virtual disks attached to the VM, the creation of the filesystem is something that you must do in the OS of the VM itself. FIO does not have support for creating filesystems. Of course each type of filesystem (NTFS, ext4, HFS, FAT, AFS, etc) has its own unique performance characteristics. The other thing to consider is if you are reading a single file or many files. FIO has parameters for controlling that. In your example, you are reading and writing just 1 single file, which might not be indicative of a real workload. For example, a web server would probably be reading from thousands of different files, and possibly writing only to a few files. A database would operate quite differently, as an example, it may have only 2 large files one for the table data and one for indexes. As an aside, there is an open source project [1] which can help with profiling disks of multiple VMs and it uses FIO in each VM to drive the workload and report back on performance. [1] https://wiki.opnfv.org/display/storperf Regards, Mark Mark Beierl SW System Sr Principal Developer Dell EMC | Cloud & Communication Service Provider Solution Mark.Beierl@xxxxxxxx On 2018-09-21, 09:51, "fio-owner@xxxxxxxxxxxxxxx on behalf of RomanS" <fio-owner@xxxxxxxxxxxxxxx on behalf of execooler@xxxxxxxxx> wrote: Hello. Could someone help to write a config to emulate a VM workload? The goal is to test a storage for VM. Each file on the VM is a disk of a VM. I tried to test the case by the following config: ioengine=posixaio randrepeat=1 norandommap=1 runtime=86400 group_reporting bs=32k time_based=1 iodepth=16 numjobs=1 rw=randrw rwmixread=50 rwmixwrite=50 size=2g [workload] filename=/storage/vm_disk But it seems the above config is not a VM workload. For the second test I created a FS on the file and mounted it. The config was almost the same, except: numjobs=20 size=85m I think the second config is more like a VM workload, than the first. Is it possible to do the same only by FIO?
