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author | Olaf Hering <olaf@aepfle.de> | 2010-12-14 18:51:55 +0000 |
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committer | Olaf Hering <olaf@aepfle.de> | 2010-12-14 18:51:55 +0000 |
commit | 6728b4d422291e306530ffa107477b6e5ac134f0 (patch) | |
tree | b459235bd50b664452184d6102f64c1abbd5ffd2 /docs/misc/xenpaging.txt | |
parent | 01db5160f3169e9dca7c855af7407862123f0fd5 (diff) | |
download | xen-6728b4d422291e306530ffa107477b6e5ac134f0.tar.gz xen-6728b4d422291e306530ffa107477b6e5ac134f0.tar.bz2 xen-6728b4d422291e306530ffa107477b6e5ac134f0.zip |
xenpaging: (sparse) documenation
Write up some sparse documentation about xenpaging usage.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Diffstat (limited to 'docs/misc/xenpaging.txt')
-rw-r--r-- | docs/misc/xenpaging.txt | 48 |
1 files changed, 48 insertions, 0 deletions
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 <guest_id> <number_of_pages> + +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/<guest_name>: + +xenpaging=32768 + +Redo the guest with 'xm create /etc/xen/vm/<guest_name>' to activate the +changes. + + +Todo: +- implement stopping of xenpaging +- implement/test live migration + + +# vim: tw=72 |