Re: [CentOS-virt] Xen4CentOS installation strangeness
I'd look in the logs for Xorg failures. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Tue, 4 Mar 2014, Pasi Kärkkäinen wrote: Date: Tue, 4 Mar 2014 21:45:01 +0200 From: Pasi Kärkkäinen pa...@iki.fi Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: Discussion about the virtualization on CentOS centos-virt@centos.org Subject: Re: [CentOS-virt] Xen4CentOS installation strangeness On Tue, Mar 04, 2014 at 02:50:40PM +0200, Peter Peltonen wrote: Hi, I have a server with Supermicro X7DVL-3 (P9) motherboard, 16G ECC RAM and LSI SAS 1068e RAID controller. I installed CentOS 6.5 64bit on the machine without any problems, but after following the Xen setup steps at [1]http://wiki.centos.org/HowTos/Xen/Xen4QuickStart which installed me the kernel 3.10.32-11.el6.centos.alt.x86_64, I encountered a problem: After Starting certmonger [OK] the screen went black and the system became unresponsive: keyboard was not working (NumLock did not respond) and SSH was not responding either. After first lockup I increased dom0 max mem to 2G, but rebooting after that produced the same result. The strange thing is, that after a third reboot everything worked ok: screen went black for a moment after Staring certmonger [OK] but after that the graphical login screen appeared and I could use the system normally. The fourth reboot went ok as well. Any ideas what could cause this kind of behaviour? No idea really.. but what you should do is to enable/configure a serial console, probably by using the IPMI SOL, so you can capture and log all the Xen and dom0 kernel boot messages.. So we can hopefully *see* what the issue is, and not have to guess :) -- Pasi Regards, Peter ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] disk io in guests causes soft lockups in guests and host processes
What helped a lot for me is to increase the read ahead drastically on guests: # Set read-ahead for optimal disk I/O blockdev --setra 16384 /dev/vda I optained this value by repeatedly timing copies and this was, for my installation at least, optimal. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Thu, 20 Feb 2014, Zoltan Frombach wrote: Date: Thu, 20 Feb 2014 19:01:10 +0100 From: Zoltan Frombach zol...@frombach.com Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: Discussion about the virtualization on CentOS centos-virt@centos.org Subject: Re: [CentOS-virt] disk io in guests causes soft lockups in guests and host processes I experienced similar issues when disk images of virtual machines were stored in qcow/qcow2 files instead of logical volumes (LVM). Using LVM gives you way better I/O performace than using qcow files. Also very important: when you partition your disk drive(s) make sure that partitions are properly aligned to the physical allocation block size of the hard drive you use. Let's say your hard drive uses 4k sectors then every partition you create must start at a 4k boundary. If your partitions are mis-aligned then you'll get terrible disk I/O performace, just like the one you have described. For more info see, for example: http://www.thomas-krenn.com/en/wiki/Partition_Alignment You can also tweak Linux to get better KVM performance. For more info you can check out these documents: http://pic.dhe.ibm.com/infocenter/lnxinfo/v3r0m0/topic/liaat/liaatbestpractices_pdf.pdf http://www.novell.com/docrep/2013/05/kvm_virtualized_io_performance.pdf Zoltan On 2/20/2014 5:53 PM, Dennis Jacobfeuerborn wrote: Hi, I have a strange phenomenon that I cannot readily explain so I wonder if anyone here can shed a light on this. The host system is a Dell r815 with 64 cores and 256G ram and has centos 6 installed. The five guests are also running centos 6 and are running as a hadoop cluster. The problem is that I see disk-io spikes in the vm's which then cause soft lockups in the guest but I also see hanging processes on the host as if the entire machine locks up for 30-60 seconds. Now I know that having all cluster members running on the same system isn't efficient and that I cannot expect good performance but what I was not expecting is that a guest make host processes hang. Does anyone have an idea what the issue could be here or how I can find out what cause for this behavior is? Regards, Dennis ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Hey
I've used both Xen and KVM and at least in benchmarks of applications I did here I didn't see much difference and since KVM is natively supported by RedHat, that's what I've been using. Obviously on this list there is mostly Xen users, and I feel like I must be missing some great advantage so I am curious, those of you who prefer Xen, why? -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Mon, 27 Jan 2014, NightLightHosts Admin wrote: Date: Mon, 27 Jan 2014 22:21:36 -1000 From: NightLightHosts Admin ad...@nightlighthosts.com Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: centos-virt@centos.org Subject: [CentOS-virt] Hey Just want to let you guys know that, although it may have been around for a bit, bringing Xen back to CentOS is awesome and I really appreciate it. I was very disappointed when RedHat dropped support as Xen is awesome. Thanks for the effort! ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
[CentOS-virt] Traffic Accounting KVM vs Xen
We've been using CentOS 6.4 for both host and KVM guests for our own internal uses here, ftp server, mail servers, web server, etc. I am getting to where we want to offer virtual servers for lease but to do so we need some method of measuring and/or limiting traffic to individual guests. I am wondering what others are using for this purpose? I know that you can look at traffic stats on the bridge on the host machine but that information is lost when the machine is rebooted. I'm wondering if there is any software that databases that information on an ongoing basis and does not lost information across reboots? Second question, what are the advantaged and disadvantages of KVM verses Xen? I played with Xen back when I had CentOS 5, but find KVM easier to work with and not much difference in performance. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
[CentOS-virt] Ethernet Not Talking
After applying a number of updates to both the host and the virtual machines, I had one virtual machine which would not talk to the network after the updates. Rebooting numerous times didn't help, I couldn't see anything wrong with either it's configuration or the bridge on the host machine. I ended up restoring that machine from an image and then re-applying the updates and then everything was okay. Amoung other things the updates included an update to glibc. I was wondering if anyone else encountered something similar and had come to a better understanding of what went wrong? -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xapi packages in CentOS xen-c6 repo: first steps
I operate an ISP, I'd be willing to provide ftp/web space for this if the bandwidth doesn't become crippling. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Tue, 2 Jul 2013, Grant McWilliams wrote: Date: Tue, 2 Jul 2013 13:24:19 -0600 From: Grant McWilliams grantmasterfl...@gmail.com Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: Discussion about the virtualization on CentOS centos-virt@centos.org Subject: Re: [CentOS-virt] Xapi packages in CentOS xen-c6 repo: first steps I'd like to test them as soon as you get ANY repo up. Grant McWilliams http://grantmcwilliams.com/ Some people, when confronted with a problem, think I know, I'll use Windows. Now they have two problems. On Tue, Jul 2, 2013 at 11:23 AM, Dave Scott dave.sc...@eu.citrix.comwrote: Hi, Thanks Mike for bringing this up. On Jul 2, 2013, at 6:15 PM, Mike McClurg mike.mccl...@citrix.com wrote: Hi list, Dave Scott has been working on a prototype of XenServer's Xapi running on stock CentOS 6.4 x86_64, with libvirt and ceph integration. He plans to demo this at the CentOS dojo in Aldershot next week. We'll be publishing the RPMs for this in a public Yum repo, and we would really like for these RPMs to eventually live in the xen-c6 repo. I was wondering what are the steps for making this happen, and also if it would be possible to make this happen before the dojo next Friday (12 July). My RPMS are in a bit of an experimental state, and I'd really appreciate people's feedback. It might be too soon to merge them into xen-c6 by next week, but it would be nice if I could point people at an online copy somewhere. Perhaps we could make a xen-c6-experimental repo or something? I could then rsync new builds regularly and put setup instructions on the CentOS wiki. Cheers, Dave We can provide a public Yum repository with these SRPMS and RPMS, if that would help. Thanks, Mike ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Very odd mouse issue
I've run into the same issue, screwing around with CONTROL-ALT-L, which is supposed to get you out of the window not in it, restarting the virtual manager, etc, eventually something seems to snap and it works, but I've not been able to determine either why it messes up or what corrects it. Another odd issue, I can get the freenx-server to work fine from guests but not from the host with the bridge. I've noticed that oddities that happen with the mouse with vnc don't happen with nx, so I'd really like to get that to work on the host. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Fri, 24 May 2013, aurfalien wrote: Date: Fri, 24 May 2013 14:24:09 -0700 From: aurfalien aurfal...@gmail.com Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: Discussion about the virtualization on CentOS centos-virt@centos.org Subject: [CentOS-virt] Very odd mouse issue Hi, I'm VNCing into my KVM server and opening virt-manager. When trying to manage a newly created guest, I'm finding the mouse pointer stays on the outside of its virtual machine window. Any insight as to why its tracking so oddly? Thanks in advance, - aurf ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
[CentOS-virt] Windows Direct-X and Virtualization
Is there anyway to run a Windows machine as a virtual machine and have direct-X display on the host console in full screen mode? If anyone has this working can you tell me what hardware, drivers, etc you are using? Thank you. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Windows Direct-X and Virtualization
The reason I asked is that I run an ISP, it would be spiffy to have one machine that I can bring up multiple OS's fully functional to troubleshoot various issues customers have. Already have virtual machines for infrastructure but they are all Linux (CentOS or Scientific Linux). -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Fri, 1 Feb 2013, SilverTip257 wrote: Date: Fri, 1 Feb 2013 19:16:52 -0500 From: SilverTip257 silvertip...@gmail.com Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: Discussion about the virtualization on CentOS centos-virt@centos.org Subject: Re: [CentOS-virt] Windows Direct-X and Virtualization On Fri, Feb 1, 2013 at 3:44 PM, Robert Dinse nan...@eskimo.com wrote: Is there anyway to run a Windows machine as a virtual machine and have direct-X display on the host console in full screen mode? If anyone has this working can you tell me what hardware, drivers, etc you are using? Thank you. There's a driver other than the default video driver (Cirrus? I think) that is supposed to be quicker for Windows (I can't seem to find the materials I read months ago). In testing I found that this driver wouldn't support higher resolutions, so I abandoned it. I don't run Windows VMs in production, so I've not experimented much with it in KVM. What I'm reading is that Direct-X support is iffy. [0] [1] [0] http://forums.fedoraforum.org/showthread.php?t=280013 [1] http://penguininside.blogspot.com/2009/06/getting-3d-acceleration-on-virtualbox.html Maybe someone will speak up who has worked with Windows on KVM quite a bit more than I have. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874 . ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt -- ---~~.~~--- Mike // SilverTip257 // ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
[CentOS-virt] Time
Friday, I moved our servers to a new co-lo facility and ran into an interesting problem with virtual machines. I did an orderly shutdown of the CentOS 6.3 host, and it in turn suspends all the guests. It took about an hour and a half to move and fire up the host. The guests, being suspended, were then an hour and a half behind and it seems ntpd does not want to correct more than 1000 seconds of error so it would not automatically adjust the clocks. I tried the -g argument which is supposed to override the 1000 second limit but it did not. I ended up having to manually set the clocks close enough for ntpd to correct. Since there is no hardware clock for the virtual machines to use when they boot, it seems that shutdown and reboot of the virtual machines probably would not have avoided this. Any suggestions for addressing this particular scenerio other than having to manually set a bunch of clocks? -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Time
I thank everyone for their input. I prefer to have the guests suspend rather than shutdown because many of my customers start things up manually and get annoyed when they come back to find them not running. Most of the time it is for a simple reboot of the host to make a new kernel or some other update active. This particular time though I had to move all the equipment to a new co-location facility because the old provider had become far too greedy. So I guess rdate -s is probably the best solution. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] (no subject)
About the only thing you can do is not run Windows, or at least that version, XP does the same thing, continuouslys spins the CPU when there aren't any user processes using time. I've heard this is resolved in Windows-7 but haven't tried it personally. -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. Knowledgeable human assistance, not telephone trees or script readers. See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874. On Fri, 7 Dec 2012, Shawn Everett wrote: Date: Fri, 7 Dec 2012 12:02:14 -0800 From: Shawn Everett sh...@tandac.com Reply-To: Discussion about the virtualization on CentOS centos-virt@centos.org To: centos-virt@centos.org Subject: [CentOS-virt] (no subject) Hi All, I have recently installed CentOS 6.3 with QEMU+KVM for Virtualization. I have successfully created a Windows 2003 VM with 4GB of RAM. The host server is an HP ML350 G8 with 24GB RAM and 24 cores. Details of one of the cores is shown below: processor : 23 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz stepping: 7 cpu MHz : 1200.000 cache size : 15360 KB physical id : 1 siblings: 12 core id : 5 cpu cores : 6 apicid : 43 initial apicid : 43 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 x2apic popcnt aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid bogomips: 3989.86 clflush size: 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: On an otherwise completely idle system I've noticed the load to be 1.0 to 1.5 range. Running top shows the culprit to be: qemu-kvm. Is this normal behavior? I would have expected the load to be pretty light. Stopping the VM restores the load to normal once again. Is there anything I can do to reduce the load? Shawn ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
