virt June 2011

virt@lists.centos.org

26 participants
12 discussions

Now on to creation of disk images
by Steve Campbell 18 Jul '11

18 Jul '11

Mr. Heron was so kind to make a suggestion that I should use disk images to install VMs. Upon further thought, I kinda like the idea. So I re-read the manual and google a little, and discover I still don't know what should be in these disk images. Should I copy the contents of the CDs to a file or what? I've got a test server at the moment with Centos 5.5 and xen installed as the host OS, but have just downloaded the 5.6 CD ISOs along with the DVD ISO, so I'll use 5.6 for my VMs. I've read about how I can create an image from something that already exists. Again, any clarity would be appreciated. steve campbell

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where can i download PV drivers for CENTOS 5.5 HVM Guest
by veerasena reddy 05 Jul '11

05 Jul '11

Hi, This is VeeraSena Reddy (shortly called VSR), recently started working on XEN. I installed CENTOS 5.5 as HVM Guest on XEN-3.4.3 and now i would like to install and test PV Drivers on this guest. Can anyone please guide me where can I get PV drivers for CENTOS 5.5 HVM guest? Thanks in Advance. Regards, VSR.

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More than 32G on memory in a domU guest?
by Norman Gaywood 29 Jun '11

29 Jun '11

I must be missing something obvious. I have a large domU guest: dom0# cat /etc/xen/turing name = "turing" uuid = "8d3383a0-f0ae-f0b1-215d-c2e04115e9fe" maxmem = 40000 memory = 40000 vcpus = 12 bootloader = "/usr/bin/pygrub" kernel = "/var/lib/xen/boot_kernel.nrTJko" ramdisk = "/var/lib/xen/boot_ramdisk.y6Gcn9" extra = "ro root=/dev/mapper/SYSTEM-root SYSFONT=latarcyrheb-sun16 LANG=en_AU.UTF-8 KEYTABLE=us console=hvc0 earlyprintk=xen" on_poweroff = "destroy" on_reboot = "restart" on_crash = "restart" vfb = [ "type=vnc,vncunused=1,keymap=en-us" ] disk = [ "phy:/dev/VM/system,xvda,w", "phy:/dev/VM/home,xvdb,w" ] vif = [ "mac=00:16:3e:7d:d0:91,bridge=xenbr0,script=vif-bridge,vifname=vif3.0" ] dom0# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 3907 16 r----- 66831.9 turing 1 40000 12 r----- 1842736.7 So it looks like I should have 40G of memory available to my guest. The guest boots like this (from /etc/grub.conf of guest): title Fedora (2.6.35.13-92.fc14.x86_64) root (hd0,0) kernel /vmlinuz-2.6.35.13-92.fc14.x86_64 ro root=/dev/mapper/SYSTEM-root SYSFONT=latarcyrheb-sun16 LANG=en_AU.UTF-8 KEYTABLE=us console=hvc0 earlyprintk=xen initrd /initramfs-2.6.35.13-92.fc14.x86_64.img However, the guest reports this: domU# grep MemTotal /proc/meminfo MemTotal: 32870604 kB What did I miss? Additional info: dom0# xm info host : neumann.une.edu.au release : 2.6.18-238.12.1.el5xen version : #1 SMP Tue May 31 14:02:29 EDT 2011 machine : x86_64 nr_cpus : 16 nr_nodes : 1 sockets_per_node : 4 cores_per_socket : 4 threads_per_core : 1 cpu_mhz : 2132 hw_caps : bfebfbff:20100800:00000000:00000940:000ce33d:00000000:00000001 total_memory : 65534 free_memory : 20354 node_to_cpu : node0:0-15 xen_major : 3 xen_minor : 1 xen_extra : .2-238.12.1.el5 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20080704 (Red Hat 4.1.2-50) cc_compile_by : mockbuild cc_compile_domain : centos.org cc_compile_date : Tue May 31 13:13:40 EDT 2011 xend_config_format : 2 -- Norman Gaywood, Computer Systems Officer University of New England, Armidale, NSW 2351, Australia ngaywood(a)une.edu.au Phone: +61 (0)2 6773 3337 http://mcs.une.edu.au/~norm Fax: +61 (0)2 6773 3312 Please avoid sending me Word or PowerPoint attachments. See http://www.gnu.org/philosophy/no-word-attachments.html

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New to virtualization - can't use more than one CD when installing a new VM
by Steve Campbell 28 Jun '11

28 Jun '11

I've done a search through all the Centos-virt emails, but can't find the answer. I'm trying to install my first VM using Centos 5.5 as the host as well as the VM OS. It starts fine using VMM, but when it asks for the second disk of 8 CDs, the first one isn't ejected, although unmounted because I can open the tray, and won't recognize that the second CD is inserted. Was I wrong in not waiting for the ejection, or am I missing something in the host setup. I'm using xen, if that matters from the 5.5 release. Thanks for any clarity. steve campbell

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common error
by Nehemiah Dacres 28 Jun '11

28 Jun '11

I am trying to install centos 5.4 on a centos 5.2 xen host. Technically this is rocks cluster and thats axillary software but the avalanch installer may be the hiccup this is what shows up in the xen log any suggestions Watching /local/domain/13/logdirty/next-active xs_read(): vncpasswd get error. /vm/84384fb8-e6a6-3a84-8027-e79b841fdc7b/vncpasswd. char device redirected to /dev/pts/4 qemu_map_cache_init nr_buckets = 10000 shared page at pfn 1ffff buffered io page at pfn 1fffd xs_read(/vm/84384fb8-e6a6-3a84-8027-e79b841fdc7b/rtc/timeoffset): read error I/O request not ready: 0, ptr: 0, port: 0, data: 0, count: 0, size: 0 I/O request not ready: 0, ptr: 0, port: 0, data: 0, count: 0, size: 0 Triggered log-dirty buffer switch -- Nehemiah I. Dacres System Administrator Advanced Technology Group Saint Louis University

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Re: [CentOS-virt] Now on to creation of disk images
by Ed Heron 28 Jun '11

28 Jun '11

On Tue, 2011-06-28 at 13:35 -0400, Steve Campbell wrote: > Ed, > > What do you mean by "ripping"? As far as the dd command you mentioned, > it appears that the ISO file itself is copied to the folder, not the > expanded iso-into-files themselves. Is this correct? If so, that's just > too easy. > > Thanks for your kind assistance. > > steve campbell Yes. By 'ripping', I'm referring to pulling the data from a disc. In this case, I'm using the dd command to create a file with the raw data from the disc. That raw data file can then be used to burn another disc or provided to a virtual machine as a virtual disc.

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Recommendations, please
by Steve Campbell 23 Jun '11

23 Jun '11

I've finally got a new machine coming that will allow me to play with virtualization. What might most of you recommend for the type of virtualization software I use. I seem to recall that xen might not be the best choice due to it's lack of development. I could be wrong, though. For the present time, all of the VMs will be Centos based. Any opinion will be appreciated. steve campbell

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Reading the new 6.0 manual - now questions
by Steve Campbell 20 Jun '11

20 Jun '11

I'm new to running VMs, so I'm hoping this hasn't been a problem question asked before. I've only glazed over the emails from this list since I've joined due to not really needing all of the great information if provides. Eric suggested I wait for Centos 6 to start loading my new VM host, and so I grabbed the RH Virtualization PDF and started digging in. Firstly, it occurred to me that Centos 6 might not provide the virtualization rpms like it did with Centos 5. RH makes this an add-on to their license. Does anyone know if the upcoming Centos 6 will provide the virtualization packages (right away or in the future)? Secondly, I'm not sure I understand the CPU allocation stuff. If I have 6 cores, it appears I can only create VMs that use 6 cores total. Using the GUI for creating a new VM will provide me with a max number I can allocate. Does this mean that I can allocate, for example, 3 VMs that use 2 cores each and never be able to create any other new VMs or does this mean I can create as many VMs as I want but only start VMs that use the max total cores or less? I should get my shiny new machine next week, the one with real virtualization capability, so some of this may be answered on my own by playing around, but until then, thought I'd get a head start on rectifying my stupidity. Thanks for any help (along with a special thanks to Eric for his original help). steve campbell

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no virtual network until vnc connection
by gisto85 16 Jun '11

16 Jun '11

Hi, I have a host with 3 guests ( 2 CentOs 1 Windows 2003 ) If I shutdown or reboot host the virtual machines starts up with no problems, If I pull down power supply when power come back host regulary startup, the vm startup ( autostart ) but vm machines network doesn't works until I connect to vm console ( e.g.: vncviewer 192.168.2.X:2 ) The host is "hp proliant ml350 g5" with network bonding (fault tolerance) CentOs 5.6, I have another identical server with 2 centos machines and no problem in case of power fault, when power come back the vm network start regulary. I attach some configuration files. Thanks in advance Egidio

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My CentOS in VMware can't find my wireless card
by liming wu 16 Jun '11

16 Jun '11

hi, i'm woo, I'm a newer to CentOS. I installed my CentOS5.3(2.6.18-128.el5) in VMware. And my wireless card is MERCURY 54U(Atheros AR5xxx).I plugged the USB card into my virtual machine, but it couldn't be found. I've tried two drivers in different time: 1)install ath5k: -------------------------------------------------------------------------------- [root@wulmcent ~]# lsmod |grep ath5k [root@wulmcent ~]# modprobe ath5k [root@wulmcent ~]# lsmod |grep ath5k ath5k 97001 0 mac80211 137545 1 ath5k cfg80211 30793 2 ath5k,mac80211 [root@wulmcent ~]# ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:F5:3D:F3 inet addr:172.3.0.5 Bcast:172.3.0.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fef5:3df3/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:16417 errors:0 dropped:0 overruns:0 frame:0 TX packets:1434 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1311085 (1.2 MiB) TX bytes:211106 (206.1 KiB) Interrupt:67 Base address:0x2000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:224 errors:0 dropped:0 overruns:0 frame:0 TX packets:224 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:15568 (15.2 KiB) TX bytes:15568 (15.2 KiB) [root@wulmcent ~]# -------------------------------------------------------------------------------- 2)install madwifi(0.9.4) -------------------------------------------------------------------------------- [root@wulmcent madwifi-0.9.4]# modprobe ath_pci [root@wulmcent madwifi-0.9.4]# lsmod|grep ath_pci ath_pci 88868 0 wlan 181904 1 ath_pci ath_hal 195536 1 ath_pci [root@wulmcent madwifi-0.9.4]# ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:F5:3D:F3 inet addr:172.3.0.5 Bcast:172.3.0.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fef5:3df3/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:17055 errors:0 dropped:0 overruns:0 frame:0 TX packets:1663 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1369453 (1.3 MiB) TX bytes:239700 (234.0 KiB) Interrupt:67 Base address:0x2000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:224 errors:0 dropped:0 overruns:0 frame:0 TX packets:224 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:15568 (15.2 KiB) TX bytes:15568 (15.2 KiB) [root@wulmcent madwifi-0.9.4]# dmesg |grep ath5k [root@wulmcent madwifi-0.9.4]# dmesg |grep ath device-mapper: multipath: version 1.0.5 loaded ath_hal: module license 'Proprietary' taints kernel. ath_hal: 0.9.18.0 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413) ath_pci: 0.9.4 -------------------------------------------------------------------------------- As the message displayed above, my system didn't find my wireless card. I don't know what to do to fix it. I need your help, thank you! ==== woo

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Drupal/MySQL performance in Xen and OpenVZ
by Einar S. Idsø 08 Jun '11

08 Jun '11

Hi, We are considering a transition from OpenVZ to Xen for our web server infrastructure. The primary task performed by the virtual servers is to run a number of Drupal sites with a MySQL backend. The webserver and MySQL servers are on separate virtual hosts. We also have a number of smaller hosts running on the same hardware (a couple of dev-servers, a logging-and-monitoring server, a secondary webserver ++). >From what I have understood, there is very little performance degradation in OpenVZ, also for IO operations, due to the use of isolated containers instead of actual virtualisation. I have also seen tests indicating detrimental IO performance of Xen IO [1]. Despite this, I have found several posters [2] suggesting the use of Xen over OpenVZ when it comes to running Drupal sites. One of the main arguments against OpenVZ is unpredictable and variable performance because VPS-hosts tend to overbook their host capacitiy. This is not an issue for us since we host our own VPSs on our own hardware so we are in complete control. So: Is there any reason Xen may be able to outperform OpenVZ for the webserver-setup I have described, or should I just continue to use OpenVZ? Cheers, Einar Sources: [1] http://www.ilsistemista.net/index.php/virtualization/1-virtual-machines-per… [2] http://2bits.com/articles/hosting-virtualization-openvz-vs-xen-which-is-bes…

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Confused by "qemu-img convert"
by MargoAndTodd 07 Jun '11

07 Jun '11

> Hi All, > > Okay. Now I am confused. > > I have a bunch of virtual machines running under Virtual Box 3.2.12. > I want to run them under KVM and drop Virtual Box from these > systems. > > Supposedly "qemu-img convert" now supports direct conversion > from vdi to whatever KVM uses. So I fired up the man page and > got really confused. Then I fired up Google and got worse > confused. > > Might I impose on some kind individual to write down a sample > run string that would show me how to do this? > > Many thanks, > -T > Is it as easy as? qemu-img convert -f vdi oldImage.vdi -O qcow2 newImage.qcow Do I need a ton of disk space to go to a full hard drive then back to a small virtual hard drive? Do I need the Virtual Box XML file for anything or just the VDI? Many thanks, -T

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virt June 2011