Xen - Revision history

PhilippeTeuwen: /* Misc notes */

2013-04-22T13:29:26Z

Misc notes

← Older revision		Revision as of 13:29, 22 April 2013
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	I tried to create two guests with each 12Gb of RAM while the host had only 16Gb in total. I would have expected a nice handling of the error but it froze xend and I could even not shutdown properly.		I tried to create two guests with each 12Gb of RAM while the host had only 16Gb in total. I would have expected a nice handling of the error but it froze xend and I could even not shutdown properly.
	<br>And, oh, BTW, no, [http://blog.coparsystems.com/?p=36&more=1&c=1&tb=1&pb=1 xen doesn't support memory overcommitment]		<br>And, oh, BTW, no, [http://blog.coparsystems.com/?p=36&more=1&c=1&tb=1&pb=1 xen doesn't support memory overcommitment]

			===Mount a DomU disk on Dom0===
			I had to transfer a large amount of data from a USB disk to a DomU.
			Easiest is to:
			* stop DomU (maybe it's possible to umount and detach block while running, I didn't try)
			* look into /etc/xen/mydomu.cfg for the disk you want, here
			disk = [
			...
			'phy:/dev/vg0/sagemath-data,xvda3,w',
			]
			* Hot plug block device to Dom0
			xm block-attach 0 phy:/dev/vg0/sagemath-data xvda3 w
			* Mount it
			mount /dev/xvda3 my-tmp-mount-point/
			When done:
			umount /dev/xvda3
			xm block-detach 0 xvda3

PhilippeTeuwen: /* Wallclock */

2012-02-02T15:59:19Z

Wallclock

← Older revision		Revision as of 15:59, 2 February 2012
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	Add cron job /etc/cron.daily/ntpdate		Add cron job /etc/cron.daily/ntpdate
	#!/bin/sh		#!/bin/sh
	ntpdate-debian		/usr/sbin/ntpdate-debian
	And		And
	chmod 755 /etc/cron.daily/ntpdate		chmod 755 /etc/cron.daily/ntpdate

PhilippeTeuwen: /* XEN tuning */

2012-02-02T15:58:20Z

XEN tuning

← Older revision		Revision as of 15:58, 2 February 2012
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	==XEN tuning==		==XEN tuning==
			===Autostart===
	If you want xen1.example.com to start automatically at the next boot of the system, then do this (if XENDOMAINS_AUTO=/etc/xen/auto in /etc/default/xendomains):		If you want xen1.example.com to start automatically at the next boot of the system, then do this (if XENDOMAINS_AUTO=/etc/xen/auto in /etc/default/xendomains):

	mkdir -p /etc/xen/auto		mkdir -p /etc/xen/auto
	ln -s /etc/xen/xen1.example.com.cfg /etc/xen/auto		ln -s /etc/xen/xen1.example.com.cfg /etc/xen/auto
			===Suspend or halt===

	By default it will attempt to save ~~runing~~ hosts when dom0 is halted. This means a "suspend-to-disk" of all domU in dom0 filesystem (/var/lib/xen/save). To prevent it and do regular shutdown of domU, edit /etc/default/xendomains and change:		By default it will attempt to save running hosts when dom0 is halted. This means a "suspend-to-disk" of all domU in dom0 filesystem (/var/lib/xen/save). To prevent it and do regular shutdown of domU, edit /etc/default/xendomains and change:
	#XENDOMAINS_SAVE=/var/lib/xen/save		#XENDOMAINS_SAVE=/var/lib/xen/save
	XENDOMAINS_SAVE=""		XENDOMAINS_SAVE=""
			===Wallclock===
			Since Xen 4, wallclocks are separated and need to be sync, e.g. in each domU (& dom0):
			apt-get install ntpdate
			Edit /etc/default/ntpdate
			NTPDATE_USE_NTP_CONF=no
			NTPSERVERS="....."
			Add cron job /etc/cron.daily/ntpdate
			#!/bin/sh
			ntpdate-debian
			And
			chmod 755 /etc/cron.daily/ntpdate

	==Misc notes==		==Misc notes==

PhilippeTeuwen: /* Guest management */

2011-04-07T09:52:29Z

Guest management

← Older revision		Revision as of 09:52, 7 April 2011
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	* xm console mynewguest		* xm console mynewguest
	** CTRL+] to detach		** CTRL+] to detach
			* xenscreen
			** attaches one screen to all domains
			** ctrl-a \ to quit properly, or ctrl-a d to detach
	* xm block-attach mynewguest phy://dev/vg0/myguest1-data2 /dev/xvda4 w		* xm block-attach mynewguest phy://dev/vg0/myguest1-data2 /dev/xvda4 w
	** to attach some device to a running guest		** to attach some device to a running guest

PhilippeTeuwen: /* XEN: installation */

2011-04-07T09:22:01Z

XEN: installation

← Older revision		Revision as of 09:22, 7 April 2011
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	* reboot		* reboot
	* cat /proc/xen/capabilities #(to check xend is running)		* cat /proc/xen/capabilities #(to check xend is running)

			To install libvirt & get some additional tools:
			* apt-get install libvirt-bin
			* Edit /etc/xen/xend-config.sxp and set
			(xend-unix-server yes)

	===XEN: guest creation===		===XEN: guest creation===

PhilippeTeuwen: /* XEN quickref */

2011-04-07T09:20:52Z

XEN quickref

← Older revision		Revision as of 09:20, 7 April 2011
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	See also [http://www.howtoforge.com/virtualization-with-xen-on-debian-lenny-amd64-p2 here] and [http://www.howtoforge.com/xen_tools_xen_shell_argo here]		See also [http://www.howtoforge.com/virtualization-with-xen-on-debian-lenny-amd64-p2 here] and [http://www.howtoforge.com/xen_tools_xen_shell_argo here]
			===Guest images===

	* xen-create-image --hostname=mynewguest		* xen-create-image --hostname=mynewguest
	** creation of config file and base filesystem		** creation of config file and base filesystem
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	* xen-update-image		* xen-update-image
	** Does apt-get update; apt-get upgrade in the guest, !!! only if guest is NOT running		** Does apt-get update; apt-get upgrade in the guest, !!! only if guest is NOT running
			===Guest start/stop===
	* xm create /etc/xen/mynewguest.cfg		* xm create /etc/xen/mynewguest.cfg
	** actual starting of guest		** actual starting of guest
		⚫	* xm shutdown mynewguest
		⚫	* xm destroy mynewguest
			===Guests info===
	* xm list		* xm list
	** Show running xen guests		** Show running xen guests
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	** Show xen version and many other info		** Show xen version and many other info
	* xm uptime		* xm uptime
			* xm top
			* xm vcpu-list
			* xm network-list mynewguest
			* xm log
			* xm dmesg
		⚫	* brctl show
			* virsh nodeinfo
			* virsh vcpuinfo mynewguest
			* virsh dominfo mynewguest
			===Guest management===
	* xm console mynewguest		* xm console mynewguest
	** CTRL+] to detach		** CTRL+] to detach
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	* xm block-list mynewguest --long		* xm block-list mynewguest --long
	* xm block-detach mynewguest 12345		* xm block-detach mynewguest 12345
⚫	* xm shutdown mynewguest
⚫	* xm destroy mynewguest
⚫	* brctl show

	==XEN tuning==		==XEN tuning==

PhilippeTeuwen: /* XEN quickref */

2011-04-07T09:12:34Z

XEN quickref

← Older revision		Revision as of 09:12, 7 April 2011
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	* xen-create-image --hostname=mynewguest		* xen-create-image --hostname=mynewguest
			** creation of config file and base filesystem
	* xen-delete-image		* xen-delete-image
	* xen-list-images		* xen-list-images
			* xen-update-image
	* ~~xen-update-image #~~ apt-get update; apt-get upgrade in the guest, !!! only if guest is NOT running		** Does apt-get update; apt-get upgrade in the guest, !!! only if guest is NOT running
	* xm create /etc/xen/mynewguest.cfg		* xm create /etc/xen/mynewguest.cfg
			** actual starting of guest
⚫	* ~~xm list #~~ Show running xen guests
			* xm list
⚫	* ~~xm info #~~ Show xen version and many other info
		⚫	** Show running xen guests
			* xm info
		⚫	** Show xen version and many other info
			* xm uptime
	* xm console mynewguest		* xm console mynewguest
	** CTRL+] to detach		** CTRL+] to detach
			* xm block-attach mynewguest phy://dev/vg0/myguest1-data2 /dev/xvda4 w
			** to attach some device to a running guest
			** not tried: "w!" for shared read/write, when the same device is attached to two different VMs
			* xm block-list mynewguest
			* xm block-list mynewguest --long
			* xm block-detach mynewguest 12345
	* xm shutdown mynewguest		* xm shutdown mynewguest
	* xm destroy mynewguest		* xm destroy mynewguest
			* brctl show

	==XEN tuning==		==XEN tuning==
	If you want xen1.example.com to start automatically at the next boot of the system, then do this (if XENDOMAINS_AUTO=/etc/xen/auto in /etc/default/xendomains):		If you want xen1.example.com to start automatically at the next boot of the system, then do this (if XENDOMAINS_AUTO=/etc/xen/auto in /etc/default/xendomains):

PhilippeTeuwen: /* XEN: guest creation */

2011-04-07T08:22:13Z

XEN: guest creation

← Older revision		Revision as of 08:22, 7 April 2011
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	Example:		Example:

	* xen-create-image --hostname=myguest1 --memory=~~12288~~ --swap=~~12288~~ --vcpus=20		* xen-create-image --hostname=myguest1 --memory=1G --swap=1G --vcpus=20
	* WARNING strangely the default root password was disabled with a '' in /etc/shadow so impossible to log in. I had to mount manually the lv (/dev/vg0/myguest1-disk) to remove the ''<br>One may prefer to setup the password interactively when creating the image with xen-create-image ... --passwd (or setup passwd=1 in /etc/xen-tools/xen-tools.conf as I've now shown in the above diff file)		* WARNING strangely the default root password was disabled with a '' in /etc/shadow so impossible to log in. I had to mount manually the lv (/dev/vg0/myguest1-disk) to remove the ''<br>One may prefer to setup the password interactively when creating the image with xen-create-image ... --passwd (or setup passwd=1 in /etc/xen-tools/xen-tools.conf as I've now shown in the above diff file)
	* lvm> lvcreate -L 1000G -n myguest1-data vg0		* lvm> lvcreate -L 1000G -n myguest1-data vg0
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	** In /etc/fstab: /dev/xvda3 /home ext4 noatime,nodiratime,errors=remount-ro 0 1		** In /etc/fstab: /dev/xvda3 /home ext4 noatime,nodiratime,errors=remount-ro 0 1
	** mount /home		** mount /home

	==XEN quickref==		==XEN quickref==
	[http://xen-tools.org/software/xen-tools/ Xen Tools], [http://xen-tools.org/software/xen-shell Xen Shell]		[http://xen-tools.org/software/xen-tools/ Xen Tools], [http://xen-tools.org/software/xen-shell Xen Shell]

PhilippeTeuwen: /* XEN tuning */

2011-04-07T07:37:22Z

XEN tuning

← Older revision		Revision as of 07:37, 7 April 2011
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	* xm destroy mynewguest		* xm destroy mynewguest
	==XEN tuning==		==XEN tuning==
	If you want xen1.example.com to start automatically at the next boot of the system, then do this:		If you want xen1.example.com to start automatically at the next boot of the system, then do this (if XENDOMAINS_AUTO=/etc/xen/auto in /etc/default/xendomains):

	ln -~~s /etc/xen/xen1.example.com.cfg~~ /etc/xen/auto		mkdir -p /etc/xen/auto
			ln -s /etc/xen/xen1.example.com.cfg /etc/xen/auto

	By default it will attempt to save runing hosts when dom0 is halted. This means a "suspend-to-disk" of all domU in dom0 filesystem (/var/lib/xen/save). To prevent it and do regular shutdown of domU, edit /etc/default/xendomains and change:		By default it will attempt to save runing hosts when dom0 is halted. This means a "suspend-to-disk" of all domU in dom0 filesystem (/var/lib/xen/save). To prevent it and do regular shutdown of domU, edit /etc/default/xendomains and change:

PhilippeTeuwen at 07:31, 7 April 2011

2011-04-07T07:31:31Z

Show changes