Date: Sat, 24 Apr 2021 13:45:27 +0200 From: Rainer Duffner <rainer@ultra-secure.de> To: dashdruid <dashdruid@protonmail.ch> Cc: "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org> Subject: Re: FreeBSD 13.0 terrible performance in KVM Message-ID: <82D1C8F0-53DA-446E-B3F7-0745C517C1A1@ultra-secure.de> In-Reply-To: <AKYOQu-q6fYoMOt_DBnDKFsHwIX2WYQiAsy0IqDO39auUExYH6L8mVG0mrSKW9G-XRSPjeuB9NxrZsYPira8Gv4NodyIx7z4w_iqxjJwS-Y=@protonmail.ch> References: <AKYOQu-q6fYoMOt_DBnDKFsHwIX2WYQiAsy0IqDO39auUExYH6L8mVG0mrSKW9G-XRSPjeuB9NxrZsYPira8Gv4NodyIx7z4w_iqxjJwS-Y=@protonmail.ch>
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> Am 24.04.2021 um 11:25 schrieb dashdruid via freebsd-stable = <freebsd-stable@freebsd.org>: >=20 > Hello List, >=20 > I hope some other folks out there running FreeBSD on KVM as well. I = set up a base VM while doing so I noticed that the disk operations are = very slow. Many times I edit a file in vim or try to run a command there = is a huge lag. It=E2=80=99s a huge and common problem that has been going on for years. I also had the same problem with XenServer. You can search bugzilla for =E2=80=9EKVM=E2=80=9C bugs, as well as the = forums. Apparently, it was mostly fixed for VMWare, but fixing for KVM is = apparently very difficult. Even more so as there are many different = versions of KVM around that all behave differently, depending on how you = configure the virtual hardware (of which there are endless variations = and permutations on how you attach with virtual devices to which virtual = PCI-bus etc.pp.). It=E2=80=99s also likely fixed on AWS (but I do not use that, so I = hardly care). E.g. when I created a KVM VM on my local workstation at work, it = performed identically (more or less) to e.g. a CentOS VM. However, if I create a VM on our on-premise Openstack cloud, it achieves = maybe 10% or 20% of the disk-IO-speed of a CentOS VM with the same = volume type. There=E2=80=99s some work going on in some differentials, but I = haven=E2=80=99t had the time to try. The problem is IMHO that most of the paid developers (for FreeBSD) these = days either use it on bare metal (hello Netflix, EMC, Netapp, Netgate = et.al.) or use it inside VMWare, where the main pain-points seem to have = been fixed. Or they even use FreeBSD=E2=80=99s own hypervisor (bhyve). It=E2=80=99s a tragedy IMO and it totally rules out FreeBSD here around = for almost all future use-cases (that are almost certainly moving to = Openstack in the future).
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