> On 25 December 2013 05:14, Qixiaozhen <[email protected]> wrote: > > Hi,all > > > > A blueprint is registered that is about shrinking the volume in thin > > provision. > > Have you got the link?
The address is https://blueprints.launchpad.net/nova/+spec/shrink-volume-in-thin-provisoning > > > Thin provision means allocating the disk space once the instance > > writes the data on the area of volume in the first time. > > > > However, if the files in the instance were deleted, thin provision > > could not deal with this situation. The space that was allocated by > > the files could not be released. > > > > So it is necessary to shrink the volume when the files are deleted in > > the instance. > > In this case the user will probably need to zero out the free space of your > filesystem too, in some cases, unless nova does that for them, which sounds a > bit dodgy. It seems that it is better that filling the free space with zero in the filesystem of the instance in offline mode. > > The operation of shrinking can be manually executed by the user with > > the web portal or CLI command or periodically in the background. > > I wondered about an "optimise disk" call. Agree with this. This shrinking operation can be a option. > > A few thoughts: > * I am not sure it can always be done "online" for all drivers, may need an > offline mode Online Shrinking: The online shrink-volume would need the additional driver. If the guest os of instance is a linux, a additional driver named 'qemu-guest-agent ' can be installed inside the guest, and the command 'fstrim' is called. More information : http://dustymabe.com/2013/06/11/recover-space-from-vm-disk-images-by-using-discardfstrim/ > * Similar operations have ways of confirming and reverting to protect against > dataloss > * Ideally keep all operations on the virtual disk, and no operations on its > content > * With chains of disks, you may want to simplify the chain too (where it makes > sense) > > John > > _______________________________________________ > OpenStack-dev mailing list > [email protected] > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list [email protected] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
