On Sun, Dec 22, 2013 at 02:57:27PM +0100, Paolo Bonzini wrote: > Linux prefers WRITE SAME to UNMAP if the limits are zero, and WRITE > SAME does not discard anything unless the device can guarantee that > the resulting block is zero. > > Setting the maximum unmap block and descriptor counts to non-zero > makes Linux choose UNMAP and fixes thin provisioning on glusterfs. > > While the maximum unmap block count can have some effect on performance, > the (suggested) maximum number of descriptors is not particularly > important so I didn't add a customization option. SCSI drivers are > used to online firmware updates so I'm not yet adding versioning support > for SCSI, but we're probably getting close to the point when it's worth > thinking about it. > > Reported-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
This patch fixes thin provisioning on gluster. Tested-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> Regards, Bharata.
