Anthony Liguori wrote: > Avi Kivity wrote: > >> Well, one user (me) has made this mistake, several times. >> > > I guess it's usage patterns. I'm pretty religious about using -snapshot > unless I have a very specific reason not to. I have never encountered > this problem myself. > >
Most users cannot use -snapshot for their workloads. >>> FWIW, the whole override thing for Xen has been an endless source of >>> pain. It's very difficult (if not impossible) to accurately >>> determine if someone else is using the disk. >>> >> What's wrong with the standard file locking API? Of course it won't >> stop non-qemu apps from accessing it, but that's unlikely anyway. >> > > Xen tries to be very smart about determining whether devices are mounted > somewhere else or not. > > I'm not talking about being too smart. Just an flock(). >>> Also, it tends to confuse people trying to do something legitimate >>> more often than helping someone doing something stupid. >>> >> -drive exclusive=off (or share=yes) >> > > The problem I have is that the default policy gets very complicated. At > first thought, I would say it's fine as long as exclusive=off was the > default for using -snapshot or using raw images. However, if you create > a VM with a qcow image using -snapshot, and then create another one > without using snapshot, you're boned. > Well then, default to exclusive=on. If you're using -shapshot you can add the extra parameter as well. > What we really need is a global configuration file so that individual > users can select these defaults according to what makes sense for them. > > In the mean time, I think the policy vs. mechanism strongly suggests > that exclusive=off should be the default (not to mention maintaining > backwards compatibility). > > The problem is that this is bad for users. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
