From: Olaf Hering Date: Tue, 14 Dec 2010 18:51:55 +0000 (+0000) Subject: xenpaging: (sparse) documenation X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=6728b4d422291e306530ffa107477b6e5ac134f0;p=xen.git xenpaging: (sparse) documenation Write up some sparse documentation about xenpaging usage. Signed-off-by: Olaf Hering Signed-off-by: Ian Jackson --- diff --git a/docs/misc/xenpaging.txt b/docs/misc/xenpaging.txt new file mode 100644 index 0000000000..e26c57ded0 --- /dev/null +++ b/docs/misc/xenpaging.txt @@ -0,0 +1,48 @@ +Warning: + +The xenpaging code is new and not fully debugged. +Usage of xenpaging can crash Xen or cause severe data corruption in the +guest memory and its filesystems! + +Description: + +xenpaging writes memory pages of a given guest to a file and moves the +pages back to the pool of available memory. Once the guests wants to +access the paged-out memory, the page is read from disk and placed into +memory. This allows the sum of all running guests to use more memory +than physically available on the host. + +Usage: + +Once the guest is running, run xenpaging with the guest_id and the +number of pages to page-out: + + chdir /var/lib/xen/xenpaging + xenpaging + +To obtain the guest_id, run 'xm list'. +xenpaging will write the pagefile to the current directory. +Example with 128MB pagefile on guest 1: + + xenpaging 1 32768 + +Caution: stopping xenpaging manually will cause the guest to stall or +crash because the paged-out memory is not written back into the guest! + +After a reboot of a guest, its guest_id changes, the current xenpaging +binary has no target anymore. To automate restarting of xenpaging after +guest reboot, specify the number if pages in the guest configuration +file /etc/xen/vm/: + +xenpaging=32768 + +Redo the guest with 'xm create /etc/xen/vm/' to activate the +changes. + + +Todo: +- implement stopping of xenpaging +- implement/test live migration + + +# vim: tw=72