Re: [libvirt] [PATCH] Don't reset user/group/security label on shared filesystems during migrate

On 05/13/2010 09:52 AM, Daniel P. Berrange wrote: > When QEMU runs with its disk on NFS, and as a non-root user, the > disk is chownd to that non-root user. When migration completes > the last step is shutting down the QEMU on the source host. THis > normally resets user/group/security label. This is bad when the > VM was just migrated because the file is still in use on the dest > host. It is thus neccessary to skip the reset step for any files > found to be on a shared filesystem > > * src/libvirt_private.syms: Export virStorageFileIsSharedFS > * src/util/storage_file.c, src/util/storage_file.h: Add a new > method virStorageFileIsSharedFS() to determine if a file is > on a shared filesystem (NFS, GFS, OCFS2, etc) Is this sufficient? Suppose I have the situation where on hypervisor A, the disk image is on a local drive, but that machine A also exports that directory via NFS. Then on hypervisor B, the disk image is viewed via NFS. When migrating a guest from machine A to B, the shutdown path on machine A will see that the file is on local storage, not NFS, and will not get your code exemption that avoids the relabel.