On Wed, 03/11 15:01, Wen Congyang wrote: > On 03/11/2015 02:49 PM, Fam Zheng wrote: > > On Wed, 03/11 14:44, Wen Congyang wrote: > >> On 03/03/2015 03:59 PM, Fam Zheng wrote: > >>> On Tue, 03/03 15:53, Wen Congyang wrote: > >>>> I test qcow2_make_empty()'s performance. The result shows that it may > >>>> take about 100ms(normal sata disk). It is not acceptable for COLO. So > >>>> I think disk buff is necessary(just use it to replace qcow2). > >>> > >>> Why not tmpfs or ramdisk? > >> > >> Another problem: > >> After failover, secondary write request will be written in (active disk)? > >> It is better to write request to (nbd target). Is there any feature can > >> be reused to implement it? > > > > You can use block commit or stream to move the data. > > When doing failover, we can use it to move the data. After failover, > I need an endless job to move the data. >
I see what you mean. After failover, does the nbd server receive more data (i.e. do you need a buffer to stash data from the other side)? If you commit (active disk) to (nbd target), all the writes will go to a single image. Fam
