KVM - Revision history

Leaky: /* Accessing a disk image from the host */ removing the disk

2017-06-12T19:12:08Z

‎Accessing a disk image from the host: removing the disk

2017-06-12T19:08:27Z

‎Networking: added accessing the disk

2017-04-16T23:27:01Z

‎Hot-add disk to running VM

2017-02-25T11:54:41Z

‎Snapshot disk images

2017-02-25T11:45:02Z

‎Ubuntu networking

2017-02-25T11:44:35Z

‎Guest kickstart: added ubuntu instructions

2015-10-07T10:57:42Z

‎Snapshot disk images

2015-01-18T17:03:18Z

‎Adding serial console after install

2014-08-23T13:06:49Z

‎Adding serial console after install: Added disk snapshot info

2014-08-19T10:40:23Z

‎Guest kickstart: Added serial console info

← Older revision		Revision as of 19:12, 12 June 2017
Line 254:		Line 254:

	# mount -t ext4 /dev/sys/root /mnt/		# mount -t ext4 /dev/sys/root /mnt/
		+
		+	After you've finished accessing the filesystem, you need to reverse the process to be free up the disk file.
		+
		+	# umount /mnt
		+	# vgchange -an sys
		+	# kpartx -dv /dev/loop1
		+	# losetup -d /dev/loop1

@@ Line 99: / Line 99: @@
   EOF
-== Adding serial console after install ==
+= Adding serial console after install =
 CentOS 6.6
@@ Line 109: / Line 109: @@
 All being well, you should then be able to use virsh console to connect and get a login prompt.
-== Hot-add disk to running VM ==
+= Hot-add disk to running VM =
   # qemu-img create newdisk.img 10G
@@ Line 138: / Line 138: @@
   Disk detached successfully
-== Snapshot disk images ==
+= Snapshot disk images =
 Disk images need to be qcow2 format to be able to have snapshots made so first of all, convert the raw disk to qcow2. With the VM powered off:
@@ Line 171: / Line 171: @@
   Before OS upgrade    2014-08-04 13:27:55 +0100 shutoff
-== Ubuntu 16.04 console via virsh ==
+= Ubuntu 16.04 console via virsh =
 Edit /etc/default/grub and change the line
@@ Line 182: / Line 182: @@
 This should allow '''virsh console $domain''' to work

@@ Line 127: / Line 127: @@
   virtio-pci 0000:00:06.0: irq 30 for MSI/MSI-X
    vdb: unknown partition table
 == Snapshot disk images ==

← Older revision		Revision as of 11:54, 25 February 2017
Line 160:		Line 160:
	After OS upgrade 2014-08-14 13:32:49 +0100 running		After OS upgrade 2014-08-14 13:32:49 +0100 running
	Before OS upgrade 2014-08-04 13:27:55 +0100 shutoff		Before OS upgrade 2014-08-04 13:27:55 +0100 shutoff
		+
		+	== Ubuntu 16.04 console via virsh ==
		+
		+	Edit /etc/default/grub and change the line
		+
		+	GRUB_CMDLINE_LINUX_DEFAULT=""
		+
		+	to read
		+
		+	GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS0,38400n8 console=tty0"
		+
		+	This should allow '''virsh console $domain''' to work

@@ Line 80: / Line 80: @@
   auto ens4
   iface ens4 inet static
-	address a.b.c.d   # Replace with your public IP
+     address a.b.c.d   # Replace with your public IP
-	netmask 255.255.255.255
+     netmask 255.255.255.255
-	dns-nameservers 8.8.8.8 8.8.4.4
+     dns-nameservers 8.8.8.8 8.8.4.4
-	post-up ip route add 192.168.123.1 dev ens4
+     post-up ip route add 192.168.123.1 dev ens4
-	post-up ip route add default via 192.168.123.1
+     post-up ip route add default via 192.168.123.1
 == Guest kickstart ==

@@ Line 73: / Line 73: @@
   # /etc/libvirt/hooks/qemu guest_name start begin -
 == Guest kickstart ==
@@ Line 86: / Line 98: @@
   default via 192.168.123.1 dev eth0
   EOF
 == Adding serial console after install ==

← Older revision		Revision as of 10:57, 7 October 2015
Line 97:		Line 97:

	All being well, you should then be able to use virsh console to connect and get a login prompt.		All being well, you should then be able to use virsh console to connect and get a login prompt.
		+
		+	== Hot-add disk to running VM ==
		+
		+	# qemu-img create newdisk.img 10G
		+
		+	# cat > newdisk.xml <<EOF
		+	disk type='file' device='disk'>
		+	<driver name='qemu' type='qcow2'/>
		+	<source file='/path/to/newdisk.img'/>
		+	<target dev='vdb' bus='virtio'/>
		+	</disk>
		+	EOF
		+
		+	# virsh attach-device <domain name> /path/to/disk.xml
		+
		+	Check the guest to see if the disk was hotplug-inserted. The kernel should be triggered, as can be checked with dmesg:
		+
		+	virtio-pci 0000:00:06.0: irq 30 for MSI/MSI-X
		+	vdb: unknown partition table

	== Snapshot disk images ==		== Snapshot disk images ==

@@ Line 90: / Line 90: @@
 == Adding serial console after install ==
-CentOS 6.5
+CentOS 6.6
-Create '''/etc/init/ttyS0.conf''' as follows:
+You'll need to make sure the grub config has console=ttyS0 as a kernel parameter.
-  cat > /etc/init/ttyS0.conf <<EOF
+  initctl start serial DEV=ttyS0 SPEED=9600
 All being well, you should then be able to use virsh console to connect and get a login prompt.

← Older revision		Revision as of 13:06, 23 August 2014
Line 112:		Line 112:

	All being well, you should then be able to use virsh console to connect and get a login prompt.		All being well, you should then be able to use virsh console to connect and get a login prompt.
		+
		+	== Snapshot disk images ==
		+
		+	Disk images need to be qcow2 format to be able to have snapshots made so first of all, convert the raw disk to qcow2. With the VM powered off:
		+
		+	# qemu-img convert -p -O qcow2 vmname.dsk vmname.dsk.qcow2
		+	# virsh edit vmname
		+
		+	Change
		+
		+	<driver name='qemu' type='raw' cache='none'/>
		+	<source file='/kvm/vmname.dsk'/>
		+
		+	to
		+
		+	<driver name='qemu' type='qcow2' cache='none'/>
		+	<source file='/kvm/vmname.dsk.qcow2'/>
		+
		+	To create a snapshot
		+
		+	# virsh snapshot-list vmname
		+	Name Creation Time State
		+	------------------------------------------------------------
		+	Before OS upgrade 2014-08-04 13:27:55 +0100 shutoff
		+
		+	# virsh snapshot-create-as vmname "After OS upgrade"
		+	Domain snapshot After OS upgrade created
		+
		+	# virsh snapshot-list vmname
		+	Name Creation Time State
		+	------------------------------------------------------------
		+	After OS upgrade 2014-08-14 13:32:49 +0100 running
		+	Before OS upgrade 2014-08-04 13:27:55 +0100 shutoff

← Older revision		Revision as of 10:40, 19 August 2014
Line 86:		Line 86:
	default via 192.168.123.1 dev eth0		default via 192.168.123.1 dev eth0
	EOF		EOF
		+
		+
		+	== Adding serial console after install ==
		+
		+	CentOS 6.5
		+
		+	Create '''/etc/init/ttyS0.conf''' as follows:
		+
		+	cat > /etc/init/ttyS0.conf <<EOF
		+	# ttyS0 - getty
		+	#
		+	# This service maintains a getty on ttyS0 from the point the system is
		+	# started until it is shut down again.
		+
		+	start on stopped rc RUNLEVEL=[2345]
		+	stop on runlevel [!2345]
		+
		+	respawn
		+	exec /sbin/agetty -L 115200 ttyS0 xterm
		+	EOF
		+
		+	Then start the process:
		+
		+	start ttyS0
		+
		+	All being well, you should then be able to use virsh console to connect and get a login prompt.