On Mon, Aug 27, 2007 at 10:19:42PM +0200, Sven Oehme wrote: > i thought it might be good to post this on qemu-devel as well, as i see > this as a general qemu / kvm / xen /whatevercomesnext issue . > > are there any plans to implement a default in qemu to prevent accessing > the same image multiple times ? Each QEMU instance is unware of each other so can't directly check this. One possiblity would be for QEMU to use fcntl() to take a lock on a disk image when opening it. With raw disk images at least, it is, however, safe to let multiple QEMU instances use it at once *provided* you have a clustered filesystem installed, rather than regular FAT or ext2/3, so one wouldn't want to exclude this use case. > i know that in xen they deal with this problem somehow xen specific. > wouldn't it be good to prevent multiple access to the same image by > default and add a switch to overwrite it ? In the scenario you mention, libvirt should probably do a sanity check for this before letting you start the guest. libvirt already supports the idea of 'shared' disk images where two or more guests can be optionally configured to have write access - basically assumes the admin requesting sharing knows what they're doing. > i corrupted a couple of virtual Linux images last week as i accidentally > started them two times .. > i opened a bug against qemu (not sure if this was a good idea) --> > https://bugzilla.redhat.com/show_bug.cgi?id=253533 > > are there any plans to ensure that this can't happen in future releases of > virt-manager with lock files in the image directory or similar ? Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=| _______________________________________________ et-mgmt-tools mailing list et-mgmt-tools@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/et-mgmt-tools
