Re: [ovirt-users] Strange drive performance over 10Gb

I was curious if anyone else has seen this or had any suggestions. I have recently began playing around with my two servers (Freenas Box and oVirt box) and their 10Gb Ethernet ports. I can access the Freenas SMB share over the 10Gb port without issue and I have been playing around with the capabilities. After finding out that my Linux Raid (MDADM) mirror is having horrible write performance, I decided to plug in an NVMe drive that I had lying around and check out its performance. *For my first test*,I added the NVMe drive as a passthrough device to a Windows guest and was able to transfer to and from Freenas box without issue. Speeds were typically ~350-400 MB/s but could drop down to 250 MB/s or so, and would top out around 525 MB/s, pretty slick! *For my second test*, I decided to mount the NVMe drive on the CentOS ovirt host and make it a local datastore. I migrated my Windows Guest to it, and decided to test and see what sort of transfer speeds I got and saw some weird results... Writing TOO the NAS worked about the same. Perhaps a little slower but at least had a steady 250-300 MB/s. Writing to the Windows Guest had a very "Fast and then slow, fast and then slow" type of throughput. I took a few screenshots: (Writing TO the NAS was fairly consistent) [image: Inline image 1] https://i.imgur.com/jWNNvfp.png (Writing TO the Windows Guest on NVMe storage) Sometimes these hit the *low 10-20 MB/s* during the transfer. [image: Inline image 2] https://i.imgur.com/aizG6n0.png [image: Inline image 3] https://i.imgur.com/AjRpR0K.png