From: libvirt-users-request(a)redhat.com Subject: libvirt-users Digest, Vol 40, Issue 24 To: libvirt-users(a)redhat.com Date: Wed, 10 Apr 2013 12:00:18 -0400 Send libvirt-users mailing list submissions to libvirt-users(a)redhat.com To subscribe or unsubscribe via the World Wide Web, visit https://www.redhat.com/mailman/listinfo/libvirt-users or, via email, send a message with subject or body 'help' to libvirt-users-request(a)redhat.com You can reach the person managing the list at libvirt-users-owner(a)redhat.com When replying, please edit your Subject line so it is more specific than "Re: Contents of libvirt-users digest..." Today's Topics: 1. performance tradeoffs/penalty (lejeczek) 2. Re: performance tradeoffs/penalty (Felicitus) ---------------------------------------------------------------------- Message: 1 Date: Wed, 10 Apr 2013 13:02:19 +0100 From: lejeczek <peljasz(a)yahoo.co.uk&gt; To: libvirt-users(a)redhat.com Subject: [libvirt-users] performance tradeoffs/penalty Message-ID: <516554CB.2000703(a)yahoo.co.uk&gt; Content-Type: text/plain; charset="utf-8"; Format="flowed" hi everybody a newbie here, hoping some experienced users/expert can honestly answer this one question, and I think I realize all other advantages libvirtoffer but simply performance, does libvirt make a user pay penalty, even if only a small amount, for using it when compared to raw qemu-kvm command line? if it does where the overhead goes? quest or host, or maybe both? lastly if overall performance is slower then how small it is comparing to all the advantages it offers? many thanks and apologies if this subject was answered already in the past -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.redhat.com/archives/libvirt-users/attachments/20130410/6183c3... ------------------------------ Message: 2 Date: Wed, 10 Apr 2013 14:45:02 +0200 From: Felicitus <felicitus(a)felicitus.org&gt; To: libvirt-users(a)redhat.com Subject: Re: [libvirt-users] performance tradeoffs/penalty Message-ID: <51655ECE.20503(a)felicitus.org&gt; Content-Type: text/plain; charset=ISO-8859-1 > does libvirt make a user pay penalty, even if only a small amount, for > using it when compared to raw qemu-kvm command line? Not that I know of, except that the libvirt daemon uses a few additional CPU cycles. Technically yes, in the spirit of the question no. Have a look at your process tree; you'll see command lines in the same way as you'd expect them to be when you start machines manually. > if it does where the overhead goes? quest or host, or maybe both? No additional CPU cycles for the guest, a few additional CPU cycles for the host to get status information and expose it via the daemon. > if overall performance is slower then how small it is comparing to all > the advantages it offers? It is completely negligible. Felicitus ------------------------------ _______________________________________________ libvirt-users mailing list libvirt-users(a)redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users End of libvirt-users Digest, Vol 40, Issue 24 *********************************************