Re: [CentOS-virt] (KVM) How can I migrate VM in a non shared storage environment?
+1 for dd + nc over ssh if necessary. This process can and probably will saturate your ethernet interface, so depending upon the amount of traffic the box pushes on the public interface the size of the partition and other factors, sometimes i add a crossover cable between unused interfaces on the 2 boxes and run the process over that interface, so it doesn't impact the running vms. Cheers -Chris On 6/24/2010 9:00 AM, centos-virt-requ...@centos.org wrote: Message: 3 Date: Thu, 24 Jun 2010 10:52:57 -0400 From: Kelvin Edmisonkel...@kindsight.net Subject: Re: [CentOS-virt] (KVM) How can I migrate VM in a non shared storage environment? To: Discussion about the virtualization on CentOS centos-virt@centos.org Message-ID:c848e989.30d95%kel...@kindsight.net Content-Type: text/plain; charset=US-ASCII On 24/06/10 7:17 AM, Poh Yong Hwangyong...@gmail.com wrote: I have a server running CentOS 5.5 with KVM capabilities. I need to migrate all the VMs to another server with the exact same hardware specs. The problem is it is running on individual harddisks, not shared storage. What is the best way to migrate to minimise downtime? I've had good success using dd and nc (netcat) to copy the contents of a disk or disk image from one machine to another, and verifying the copy was successful with a md5sum or sha1sum of both the original and copied disk. Kelvin -- ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt End of CentOS-virt Digest, Vol 34, Issue 13 *** ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Xen domU default gateway missing/ARP table full
Ken, I think Pasi's on to something there, I bet the GATEWAY command in ifcfg-eth0 is mistyped or has a syntax error. In the interem, however, a better hack might be to move the route statement from rc.local, which only runs at boot, to /etc/sysconfig/network-scripts/route-eth0 . That will enable the network service to restart or the eth0 interface to downup without removing the default route. -Chris On Thu, Nov 19, 2009 at 8:04 AM, Pasi Kärkkäinen pa...@iki.fi wrote: On Thu, Nov 19, 2009 at 10:03:05AM -0500, Ken Bass wrote: Pasi Kärkkäinen wrote: I usually specify the default gateway in /etc/sysconfig/network-scripts/ifcfg-eth0 and it works just fine. Actually, I tried putting the GATEWAY in the specific ifcfg-eth0, as well as the global /etc/sysconfig/network and it seems to be ignored. Of course things 'appear' to work just fine, but the route that is setup is default * 0.0.0.0 U 0 00 eth0 INSTEAD OF: default router.example.com 0.0.0.0 UG0 0 0 eth0 The former seems to cause all arp entries to be queried and cached. The latter works correctly. Both 'appear to work'. Does the route on your domU look like the second entry? Yes, the routing table is correct for my domUs. I have never noticed/seen GATEWAY getting ignored.. Maybe your netmask is wrong, so the GATEWAY IP is unreachable? -- Pasi ___ 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] virsh autostart: cannot set autostart for transient domain
Hello all, I'm running a newly installed CentOS 5.4 KVM host and am running into problems setting guests up to autostart. Has anyone seen and/or overcome this issue? [r...@virt04 ~]# virsh autostart guest02 error: Failed to mark domain guest02 as autostarted error: internal error cannot set autostart for transient domain Just for kicks I tried symlinking /etc/libvirt/guest02.xml and /etc/libvirt/autostart/guest02.xml, but to no avail. I've entered virsh create /root/vms/guest2.xml into /etc/rc.d/rc.local for now. Thanks Christopher Hunt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] Migrating from KVM to XEN - kernel panic
Pasi, Thanks very much for the tip. That did give me some additional information: Scanning and configuring dmraid supported devices Scanning logical volumes Reading all physical volumes. This may take a while... Activating logical volumes Volume group virt01vg00 not found Creating root device. Mounting root filesystem. mount: could not find filesystem '/dev/root' Setting up other filesystems. Setting up new root fs setuproot: moving /dev failed: No such file or directory no fstab.sys, mounting internal defaults setuproot: error mounting /proc: No such file or directory setuproot: error mounting /sys: No such file or directory Switching to new root and running init. unmounting old /dev unmounting old /proc unmounting old /sys switchroot: mount failed: No such file or directory Kernel panic - not syncing: Attempted to kill init! This brings me back to suspecting the problem is in the different file structures. I'm still trying to wrap my head around the other replies in this thread. On Sat, Nov 7, 2009 at 2:24 PM, Pasi Kärkkäinen pa...@iki.fi wrote: On Fri, Nov 06, 2009 at 11:49:41AM -0800, Christopher Hunt wrote: First let me say that I'm not a sysadmin, but am simply wearing that hat this week so please excuse my ignorance. I need to temporarily move some virtual servers from a CentOS-KVM platform to a CentOS-XEN platform while I do some upgrades to the CentOS box. I've created a local LV, and used DD and SCP to transfer the block device from the VKM machine to the XEN machine. For quite a while I struggled with the Error: (2, 'Invalid kernel', 'xc_dom_parse_elf_kernel: ELF image has no shstrtab\n') error but thanks to Nick Couchman from [1] http://lists.xensource.com/archives/html/xen-users/2008-03/msg00603.html, I've passed that. Now I'm stuck with a kernel panic situation. Unfortunately the kernel panic error doesn't appear using xm console and flashes so quickly through virt-viewer that I can't get any details. Stop the guest and edit /etc/xen/guest cfgfile. Remove (or comment out) the vfb line, and then restart the guest. Now you get the full console output to xm console. -- Pasi ___ 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] Migrating from KVM to XEN - kernel panic
Well that was more helpful than I could reasonable hope for but alas, the
error didn't change much:
device-mapper: dm-raid45: initialized v0.2594l
Waiting for driver initialization.
Scanning and configuring dmraid supported devices
Scanning logical volumes
Reading all physical volumes. This may take a while...
Found volume group vg00 using metadata type lvm2 ## this is the VG on
the KVM host
Activating logical volumes
Volume group virt01vg00 not found ## this is the VG on the XEN host
Creating root device.
Mounting root filesystem.
kjournald starting. Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
Setting up other filesystems.
Setting up new root fs
setuproot: moving /dev failed: No such file or directory
no fstab.sys, mounting internal defaults
setuproot: error mounting /proc: No such file or directory
setuproot: error mounting /sys: No such file or directory
Switching to new root and running init.
unmounting old /dev
unmounting old /proc
unmounting old /sys
ERROR opening /dev/console: No such file or directory
Trying to use fd 0 instead.
WARNING: can't access (null)
exec of init ((null)) failed!!!: Bad address
Kernel panic - not syncing: Attempted to kill init!
I wonder if i need to mount the block device and edit fstab?
Christopher Hunt
On Mon, Nov 9, 2009 at 11:09 AM, Christopher G. Stach II c...@ldsys.netwrote:
- Christopher Hunt dharmach...@gmail.com wrote:
This brings me back to suspecting the problem is in the different file
structures. I'm still trying to wrap my head around the other replies
in this thread.
mkinitrd in dom0 with xenblk and xennet and use that new initrd for the
guests. After you get the guests up and running, install kernel-xen in each
one and switch to using pygrub. The following should handle the first part,
but no warranties implied. :)
mkinitrd --with=xenblk --with=xennet --preload=xenblk --preload=xennet
/boot/initrd-2.6.18-164.6.1.el5xen-domU.img 2.6.18-164.6.1.el5xen
for i in /etc/xen/guest[0-9]*; do
cp ${i} ${i}.bak
sed -i '/^ramdisk/cramdisk =
/boot/initrd-2.6.18-164.6.1.el5xen-domU.img' ${i}
done
--
Christopher G. Stach II
___
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] Migrating from KVM to XEN - kernel panic
ugh after doing inglorious battle, I return. It's definitely situation (1). The error messages haven't changed. Inside the init file, should the paths references be from the point of view of Dom0? lvm vgchange -ay --ignorelockingfailure vg00 resume /dev/vg00/swap00 echo Creating root device. mkrootdev -t ext3 -o defaults,ro /dev/mapper/vg00-root echo Mounting root filesystem. mount /sysroot echo Setting up other filesystems. setuproot echo Switching to new root and running init. switchroot Also, should the xen host config file (/etc/xen/guest02) root parameter point to the dom0 root or the block device for the domU? root = /dev/mapper/virt01vg00-c5root00 ro ##dom0's root file system Thanks very much, Christopher Hunt On Mon, Nov 9, 2009 at 12:54 PM, Christopher G. Stach II c...@ldsys.netwrote: - Christopher G. Stach II c...@ldsys.net wrote: 1. mkinitrd --with=xenblk --with=xennet --preload=xenblk --preload=xennet img version (yes, that's the original one without the fstab) 2. gunzip -c /boot/initrd-blah.img /root/blah 3. mkdir /mnt/blah 4. mount -o loop /root/blah /mnt/blah 5. vi /mnt/blah/init change occurrences of dom0 VG to guest VG change dom0 root device name to guest root device name 6. umount /mnt/blah 7. gzip -c /root/blah /boot/initrd-blah.img If you followed these directions, you're probably scratching your head. I screwed up. The initrd is actually a cpio archive, so: 1. mkinitrd --with=xenblk --with=xennet --preload=xenblk --preload=xennet img version (yes, that's the original one without the fstab) 2. mkdir /root/initrd-blah 3. cd /root/initrd-blah 4. gunzip -c /boot/initrd-blah.img | cpio -idmv 5. vi /root/initrd-blah/init 6. find . -print | cpio -o | gzip -c /boot/initrd-blah.img -- Christopher G. Stach II ___ 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
