Happy to help! The current external version of rhel_iotest.sh only supports RHEL 6 & 7 (we're working on getting RHEL 8 support pushed). If you want to shoot me an email at Jim.Kuell@sas.com, I'd be happy to send you over a temporary version that will work with RHEL 8.   EDIT: It looks like the RHEL 8 update has been pushed to the external version after all. I'll see if I can get the doc updated to properly reflect that. ... View more

@epower What OS and version are you running? If RHEL 7 or 8, I would recommend using the rhel_iotest.sh tool (https://support.sas.com/kb/59/680.html) to measure your IO throughput over the standard UNIX version. Rhel_iotest.sh is much easier to run since you only need to pass it the target file system and it handles calculating the rest of the parameters needed.   As for the nvme striping (note this also applies to RHEL), we typically recommend using lvm2 to stripe these drives together. A good place to start is with a 64 KB stripesize and a large, static value for readahead (8 MB+). I've found a 16 MB readahead is a good fit for my workload, but you can always monitor and adjust these values down the road if needed. When using lvm2, it's also important to make sure the drives ultimately get striped and not concatenated.   Let me know if you have any questions or would like some help putting together commands for setting up/striping the nvme drives.   You can find our RHEL OS tuning best practices here: RHEL 6 & 7: https://access.redhat.com/sites/default/files/attachments/optimizingsasonrhel6and7_2.pdf RHEL 8: https://communities.sas.com/t5/Administration-and-Deployment/Interim-RHEL-8-Tuning-Guidelines-for-SAS/m-p/798681 ... View more