Joe, I appreciate your continuous work. Is that read or write? The difference between Type 0 and 1 should only show up in write path. So is it write test? And what is the unit of each result? > So maybe it's just volume of IO that's causing the problem? What's > the difference between Type 0 and Type 1? In the code I notice you > have 'rambuf' structures, are you caching IO in memory? "rambuf" is a temporary space that every write data comes in. 127*4KB data are once stored there and 4KB metadata section are added then it becomes a log and flushed to the cache device sequentially (512KB each). By the way, I think more clearer discussion can be done if tests are done on physical machines to isolate things relevant to VM. I will also add these tests to dmts later and run on my machine. But, it will be much better if we have good server with RAID-ed backing store and the newest SSD (How would it be if it's PCI-e SSD)... - Akira On 12/10/14 9:33 PM, Joe Thornber wrote: > On Wed, Dec 10, 2014 at 08:00:13PM +0900, Akira Hayakawa wrote: >> Hi, Joe >> >> Thanks for continuous evaluation. > > Some more details: > > dd, with block size 512b > ------------------------ > > raw spindle : 143 > writeboost Type 0: 137 > writeboost Type 1: 130 > > dd, with block size 4k > ---------------------- > > raw spindle : 31 > writeboost Type 0: 29 > writeboost Type 1: 81 > > > dd, with block size 64m > ----------------------- > > raw spindle : 8.9 > writeboost Type 0: 32 > writeboost Type 1: 72 > > > > So maybe it's just volume of IO that's causing the problem? What's > the difference between Type 0 and Type 1? In the code I notice you > have 'rambuf' structures, are you caching IO in memory? > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
