Re: [libvirt] [Qemu-devel] live snapshot wiki updated

The 20/07/11, Daniel P. Berrange wrote: > To make the decision whether the filename from QEMU is valid, we have > to parse the master image header data to see if the filename actually > matches the backing file required by the image assigned to the guest. Actually, libvirt should not have to worry if the filename provided by QEMU is valid. I think it should trust QEMU. If QEMU doesn't provide information others can trust; it should be fixed at QEMU side.

> We're not fighting over the internals of metadata. We just need to know > ahead of launching QEMU, what backing files an image has & what format > they are in. We do that by reading at the metadata headers of the disk > images. We never attempt to write to the disk images. Either someone > provides a library todo that, or we write the probing code for each > file format in libvirt. Currently we have the latter. This is what I would call "fighting with QEMU internals". How do you prevent from concurrency access and modifications? Ideally speacking libvirt should be able to co-exist with foreign implementations, all requesting QEMU.