lqs2mem
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juergh
Convert libvirt-QEMU-save (LQS) files to raw memory files
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+ - NOTE: Development of this tool has stopped in favor of its replacement +
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lqs2mem.py (https://github.com/juergh/lqs2mem.py) + -
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Acquiring memory from a Libvirt/KVM virtual machine
Use the virsh 'dump' command to save the virtual machine's state to a file on disk without stopping the virtual machine, or the virsh 'save' command to save the virtual machine's state to a file on disk and stop the virtual machine. A virtual machine stopped with the 'save' command can later be restarted with the 'restore' command.
The output of the 'dump' command is a file in QEMU-savevm format. The output of the 'save' command is a file in Libvirt-QEMU-save (LQS) format. An LQS file contains a header with the virtual machine's Libvirt configuration, followed by QEMU-savevm format data. The QEMU-savevm format captures the state of a virtual machine in a series of sections, each section representing the state of a device. For example, there is CPU state, RAM state, block device state, and more.
Converting virtual machine dumps to raw memory files
The lqs2mem tool converts LQS or QEMU-savevm files into raw physical memory images. It reads data from the RAM sections of an LQS or QEMU-savevm input file and writes it to a file in which each byte corresponds to a byte of the virtual machine's physical memory. That is, reading from position x of a raw physical memory image is equivalent to reading from physical address x of memory.
A typical LQS or QEMU-savevm file contains different memory section. The lqs2mem tool can be used to list the available sections and then convert the specified section to a raw memory file.
Examples
List the available sections:
$ lqs2mem -l instance-00000d93.save section = pc.ram size = 512 [MB] 536870912 [Bytes] section = pc.bios size = 128 [KB] 131072 [Bytes] section = pc.rom size = 128 [KB] 131072 [Bytes] section = vga.vram size = 16 [MB] 16777216 [Bytes] section = 0000:00:02.0/cirrus_vga.rom size = 64 [KB] 65536 [Bytes] section = 0000:00:03.0/virtio-net-pci.rom size = 32 [KB] 32768 [Bytes]
Write the virtual machine's main memory (pc.ram section) to a raw memory file:
$ lqs2mem -w pc.ram instance-00000d93.save instance-00000d93.ram section = pc.ram size = 512 [MB] 536870912 [Bytes] section = pc.bios size = 128 [KB] 131072 [Bytes] section = pc.rom size = 128 [KB] 131072 [Bytes] section = vga.vram size = 16 [MB] 16777216 [Bytes] section = 0000:00:02.0/cirrus_vga.rom size = 64 [KB] 65536 [Bytes] section = 0000:00:03.0/virtio-net-pci.rom size = 32 [KB] 32768 [Bytes] Wrote 536870912 bytes from section 'pc.ram' to file instance-00000d93.ram
juergh