Good test, non-buffered dom0 dd write speed is similar with tap2.
I'll likely stay with the QEMU backend. Are there any best practises
regarding security, at least if QEMU can operate under non-root account?
Cheers
--
Karel
On 12.9.2015 10:51, Pasi Kärkkäinen wrote:
On Sat, Sep 12, 2015 at 01:35:48AM +0200, Karel Hendrych wrote:
Comparing simple dd bs=1M count=10000 on dom0 vs domU. Qemu driver
is achieving pretty much the same like dom0.
So you're measuring buffered speed. Try measuring non-buffered (iflag=direct or oflag=direct, depending if you're reading or writing).
-- Pasi
Thanks
--
Karel
On 7.9.2015 21:45, Pasi Kärkkäinen wrote:
On Mon, Sep 07, 2015 at 05:47:39PM +0200, Karel Hendrych wrote:
...
changing from: <driver name='file'/> to: <driver name='tap2'/> makes
the domain start without QEMU.
However I see much better performance with QEMU (close to dom0,
tested using simple dd writes) than with tap2 driver. Is that
expected?
How did you measure it? buffered or direct io?
-- Pasi
What's best practise to file based storage on latest CentOS6-xen
(Kernel 3.18.17, Xen 4.4.2-7)
Are there any guides around running QEMU on CentOS6-xen as non-root user?
Cheers
--
Karel
On 7.9.2015 17:42, Karel Hendrych wrote:
Hi, spot on!
On 6.9.2015 12:56, Pasi Kärkkäinen wrote:
On Sun, Sep 06, 2015 at 09:08:50AM +0200, Karel Hendrych wrote:
Hi, after migrating to libvirt/libxl according to:
Hi,
https://wiki.centos.org/HowTos/Xen/Xen4QuickStart/Xen4Libvirt
I've noticed that my Xen PV domains are being launched by
qemu-system-i386 running under root privileges.
I am wondering why is this? Previously no qemu process was used.
If qemu is needed for some reason, are there any guidelines for
non-root operation?
In general qemu is used for the following purposes:
- for certain domU disk backend types (image files), and/or if there's
no blktap driver in dom0 kernel.
- domU graphical console (PVFB) VNC server, if it's enabled for the domU.
--
Karel Hendrych
-- Pasi
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