similar to: Performance tunning CentOS / Xen

Hi experts, Q1:What''s the different for "dom0_max_vcpus=4 dom0_vcpus_pin" and "dom0_max_vcpus=4" ? which will get better performance Q2: dom0_max_vcpus=4 means "core0-3 will be just used by dom0" or means "4 cores(not dedicate cores) will be used by dom0, eg: core2-5 or core3-6? Q3.what does mean "nosmp" , xen, dom0,domU, will just use one

Hi experts, Q1:What''s the different for "dom0_max_vcpus=4 dom0_vcpus_pin" and "dom0_max_vcpus=4" ? which will get better performance Q2: dom0_max_vcpus=4 means "core0-3 will be just used by dom0" or means "4 cores(not dedicate cores) will be used by dom0, eg: core2-5 or core3-6? Q3.what does mean "nosmp" , xen, dom0,domU, will just use one

Hi, Seeing a drop-off in iops when more vcpu''s are added:- 3.8.2 kernel/xen-4.2.1/single domU/LVM backend/8GB RAM domU/2GB RAM dom0 dom0_max_vcpus=2 dom0_vcpus_pin domU 8 cores fio result 145k iops domU 10 cores fio result 99k iops domU 12 cores fio result 89k iops domU 14 cores fio result 81k iops ioping . -c 3 4096 bytes from . (ext4 /dev/xvda1): request=1 time=0.1 ms 4096 bytes

Hello everyone, I just put together a brand new system, and I''m getting the following when I try to start a domU: > [ 1902.049066] xend[12924]: segfault at b9ff6cd8 ip 00007f36c474afe1 sp 00007f36b9ff6af8 error 4 in libxenguest.so.4.0.0[7f36c4730000+24000] This is on an AMD CPU with the AVX instructions, and I already have this in my grub.cfg: > multiboot /xen-4.1.2.gz

Hey, I''m more a reader than a poster on this list but Recently I installed CentOS 6.2 with myoung XEN Dom0 kernel and 4.1.2 hypervisor, at first everything went smooth, DomUs run like a charm and so on, but my serial console is gone for good tried dmesg | grep tty which spits out: uname -r 2.6.32-131.21.1.el6.xendom0.x86_64 dmesg | grep tty console [tty0] enabled Weirdest thing when

Hello, After saving and restoring a DomU (teste on the same server), doing a reboot to the newly restored domU will cause it to crash. This happens on PV and PVHVM domUs. I am using qemu upstream for the HVM guests, but I don''t really think it matters as long as PV guests behave the same. I want to confirm this if possible, before submitting a bug report and more details. I am using

Dear All I am using Centos 7 with Xen 4.6 on a Dell Poweredge T430 When the machine boots, after the 'Scrubbing Free RAM' message, I get a screen filled with little white squares until the login prompt, so I cannot see what is happening as the machine boots. Also there is nothing on the screen when I reboot. My /etc/default/grub is GRUB_DISTRIBUTOR="$(sed 's, release

Hi All it is possible to tune dom0/domU for better IO/network performance? Since I have changed to Cenots7 dom0, I have a really poor IO performance inside a PV VM. I have already done what is described on http://wiki.xenproject.org/wiki/Tuning_Xen_for_Performance It is better now but still significantly worse than with centos6 dom0 my settings: xen parameter: dom0_mem=1024M cpufreq=xen

Hi, I seem to have an interesting issue with vif-route. This is after an update to Xen 4.2.1, switching from xm to xl. I have 10 PV domUs on the host and two FreeBSD ones. All the PV domUs are now working nicely. Since FreeBSD has always been just slightly broken as PV I chose a HVM domU for those, but with PV drivers. Those PV drivers all blew up now after the upgrade. I''m now trying

I use xen 4.0(dom0 is suse11.sp1,2.6.32 x86_64) on Dell R710 with PERC H700 RAID adapter. --Intel(R) Xeon(R) CPU E5620 @ 2.40GHz --8 CPU cores. --Memory 64G --RAID5 4.5T When I dedicated (pin) a CPU core only for dom0 use. (I specify "dom0_max_vcpus=1 dom0_vcpus_pin" options for Xen) I got dom0 kernel panic error(pin-1-5.30.bmp) When I pin 2 core to dom0, the dom0 system can boot up,

With GPLPV under 2.6.30, GPLPV gets the following from the ring: ring slot n (first buffer): status (length) = 54 bytes offset = 0 flags = NETRXF_extra_info (possibly csum too but not relevant) ring slot n + 1 (extra info) gso.size (mss) = 1460 Because NETRXF_extra_info is not set, that''s all I get for that packet. In the IP header though, the total length is 1544 (which in itself

With GPLPV under 2.6.30, GPLPV gets the following from the ring: ring slot n (first buffer): status (length) = 54 bytes offset = 0 flags = NETRXF_extra_info (possibly csum too but not relevant) ring slot n + 1 (extra info) gso.size (mss) = 1460 Because NETRXF_extra_info is not set, that''s all I get for that packet. In the IP header though, the total length is 1544 (which in itself

If this has already been done, please forgive me. However, if not, I''d like to submit this as a mechanism for generating a bootable grub2 stanza for hypervisors. As the /etc/grub.d/* files rely on defaults in /etc/default/grub, I added the following Xen specific variable: GRUB_CMDLINE_XEN_DEFAULT="console=com1 115200,8n1 dom0_mem=512M dom0_max_vcpus=1 dom0_vcpus_pin=true

Hi All, Running into temporary pauses in our VMs which correspond to these errors in dmesg on the dom0: [1721485.352560] SLUB: Unable to allocate memory on node -1 (gfp=0x20) [1721485.352563] cache: kmalloc-2048, object size: 2048, buffer size: 2048, default order: 3, min order: 0 [1721485.352566] node 0: slabs: 81, objs: 1296, free: 0 [1721485.352576] swapper: page allocation failure:

Dear George, Thanks for the input and ideas. Unfortunately bootscrub=false dos not work, not does setting nothing for vga, still get the 'Little white squares'! I am asking the xen-users as you suggest Regards, Francis From: "George Dunlap" <dunlapg at umich.edu> To: "Francis Greaves" <francis at choughs.net>, "centos-virt" <centos-virt

Yes I usually work headless, but I have been setting it up from new, so need to see what is going on. Regards Francis From: "Scot P. Floess" <sfloess at nc.rr.com> To: "Francis Greaves" <francis at choughs.net> Cc: "centos-virt" <centos-virt at centos.org> Sent: Monday, 22 February, 2016 17:02:12 Subject: Re: [CentOS-virt] Garbled screen

-------- Forwarding messages -------- From: test <www.ryanliang@126.com> Date: 2012-11-13 17:14:18 To: xen-announce@lists.xen.org Subject: Fwd: Installing XEN on Centos 6.3 X86_64 ... Problem xen not starting...!!!//I have the same problem.... http://www.howtoforge.com/forums/showthread.php?t=58226 Hi, I followed tutorial

On a selection of boxes, ntpd running in Xen Dom0 reproducibly exhibits extermely high noise/jitter. Switching back to -default, non-xen kernel ntpd runs with very low jitter/noise. Question -- how can I ''tame'' ntpd noise & jitter when running in Dom0? Is the problem a config issue, or a bug? Already reported this downstream; everybody''s "stumped".

On a selection of boxes, ntpd running in Xen Dom0 reproducibly exhibits extermely high noise/jitter. Switching back to -default, non-xen kernel ntpd runs with very low jitter/noise. Question -- how can I ''tame'' ntpd noise & jitter when running in Dom0? Is the problem a config issue, or a bug? Already reported this downstream; everybody''s "stumped".

Hi all, I''ve got a couple of questions regarding the current status of nvidia with Xen, since it is well known that nvidia doesn''t work as smooth at the moment with Xen (comparing to ati). My current goal is to use one nvidia gtx460 card and the onboard intel hd4000 on dom0, and then do passthrough for another nvidia gtx460 to a Windows domU. I know there are patches