Revision 13a2e80f qemu-doc.texi
| b/qemu-doc.texi | ||
|---|---|---|
| 743 | 743 |
show all USB host devices |
| 744 | 744 |
@item info capture |
| 745 | 745 |
show information about active capturing |
| 746 |
@item info snapshots |
|
| 747 |
show list of VM snapshots |
|
| 746 | 748 |
@end table |
| 747 | 749 |
|
| 748 | 750 |
@item q or quit |
| ... | ... | |
| 777 | 779 |
@item log item1[,...] |
| 778 | 780 |
Activate logging of the specified items to @file{/tmp/qemu.log}.
|
| 779 | 781 |
|
| 780 |
@item savevm filename |
|
| 781 |
Save the whole virtual machine state to @var{filename}.
|
|
| 782 |
@item savevm [tag|id] |
|
| 783 |
Create a snapshot of the whole virtual machine. If @var{tag} is
|
|
| 784 |
provided, it is used as human readable identifier. If there is already |
|
| 785 |
a snapshot with the same tag or ID, it is replaced. More info at |
|
| 786 |
@ref{vm_snapshots}.
|
|
| 782 | 787 |
|
| 783 |
@item loadvm filename |
|
| 784 |
Restore the whole virtual machine state from @var{filename}.
|
|
| 788 |
@item loadvm tag|id |
|
| 789 |
Set the whole virtual machine to the snapshot identified by the tag |
|
| 790 |
@var{tag} or the unique snapshot ID @var{id}.
|
|
| 791 |
|
|
| 792 |
@item delvm tag|id |
|
| 793 |
Delete the snapshot identified by @var{tag} or @var{id}.
|
|
| 785 | 794 |
|
| 786 | 795 |
@item stop |
| 787 | 796 |
Stop emulation. |
| ... | ... | |
| 895 | 904 |
|
| 896 | 905 |
Since version 0.6.1, QEMU supports many disk image formats, including |
| 897 | 906 |
growable disk images (their size increase as non empty sectors are |
| 898 |
written), compressed and encrypted disk images. |
|
| 907 |
written), compressed and encrypted disk images. Version 0.8.3 added |
|
| 908 |
the new qcow2 disk image format which is essential to support VM |
|
| 909 |
snapshots. |
|
| 899 | 910 |
|
| 900 | 911 |
@menu |
| 901 | 912 |
* disk_images_quickstart:: Quick start for disk image creation |
| 902 | 913 |
* disk_images_snapshot_mode:: Snapshot mode |
| 914 |
* vm_snapshots:: VM snapshots |
|
| 903 | 915 |
* qemu_img_invocation:: qemu-img Invocation |
| 904 | 916 |
* disk_images_fat_images:: Virtual FAT disk images |
| 905 | 917 |
@end menu |
| ... | ... | |
| 926 | 938 |
write back to the raw disk images by using the @code{commit} monitor
|
| 927 | 939 |
command (or @key{C-a s} in the serial console).
|
| 928 | 940 |
|
| 941 |
@node vm_snapshots |
|
| 942 |
@subsection VM snapshots |
|
| 943 |
|
|
| 944 |
VM snapshots are snapshots of the complete virtual machine including |
|
| 945 |
CPU state, RAM, device state and the content of all the writable |
|
| 946 |
disks. In order to use VM snapshots, you must have at least one non |
|
| 947 |
removable and writable block device using the @code{qcow2} disk image
|
|
| 948 |
format. Normally this device is the first virtual hard drive. |
|
| 949 |
|
|
| 950 |
Use the monitor command @code{savevm} to create a new VM snapshot or
|
|
| 951 |
replace an existing one. A human readable name can be assigned to each |
|
| 952 |
snapshots in addition to its numerical ID. |
|
| 953 |
|
|
| 954 |
Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
|
|
| 955 |
a VM snapshot. @code{info snapshots} lists the available snapshots
|
|
| 956 |
with their associated information: |
|
| 957 |
|
|
| 958 |
@example |
|
| 959 |
(qemu) info snapshots |
|
| 960 |
Snapshot devices: hda |
|
| 961 |
Snapshot list (from hda): |
|
| 962 |
ID TAG VM SIZE DATE VM CLOCK |
|
| 963 |
1 start 41M 2006-08-06 12:38:02 00:00:14.954 |
|
| 964 |
2 40M 2006-08-06 12:43:29 00:00:18.633 |
|
| 965 |
3 msys 40M 2006-08-06 12:44:04 00:00:23.514 |
|
| 966 |
@end example |
|
| 967 |
|
|
| 968 |
A VM snapshot is made of a VM state info (its size is shown in |
|
| 969 |
@code{info snapshots}) and a snapshot of every writable disk image.
|
|
| 970 |
The VM state info is stored in the first @code{qcow2} non removable
|
|
| 971 |
and writable block device. The disk image snapshots are stored in |
|
| 972 |
every disk image. The size of a snapshot in a disk image is difficult |
|
| 973 |
to evaluate and is not shown by @code{info snapshots} because the
|
|
| 974 |
associated disk sectors are shared among all the snapshots to save |
|
| 975 |
disk space (otherwise each snapshot would have to copy the full disk |
|
| 976 |
images). |
|
| 977 |
|
|
| 978 |
When using the (unrelated) @code{-snapshot} option
|
|
| 979 |
(@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
|
|
| 980 |
but they are deleted as soon as you exit QEMU. |
|
| 981 |
|
|
| 982 |
VM snapshots currently have the following known limitations: |
|
| 983 |
@itemize |
|
| 984 |
@item |
|
| 985 |
They cannot cope with removable devices if they are removed or |
|
| 986 |
inserted after a snapshot is done. |
|
| 987 |
@item |
|
| 988 |
A few device drivers still have incomplete snapshot support so their |
|
| 989 |
state is not saved or restored properly (in particular USB). |
|
| 990 |
@end itemize |
|
| 991 |
|
|
| 929 | 992 |
@node qemu_img_invocation |
| 930 | 993 |
@subsection @code{qemu-img} Invocation
|
| 931 | 994 |
|
Also available in: Unified diff