{"action":"created","issue":{"url":"https://api.github.com/repos/akiradeveloper/dm-writeboost/issues/71","labels_url":"https://api.github.com/repos/akiradeveloper/dm-writeboost/issues/71/labels{/name}","comments_url":"https://api.github.com/repos/akiradeveloper/dm-writeboost/issues/71/comments","events_url":"https://api.github.com/repos/akiradeveloper/dm-writeboost/issues/71/events","html_url":"https://github.com/akiradeveloper/dm-writeboost/issues/71","id":95266833,"number":71,"title":"Further writeback optimisation possible?","user":{"login":"disaster123","id":861558,"avatar_url":"https://avatars.githubusercontent.com/u/861558?v=3","gravatar_id":"","url":"https://api.github.com/users/disaster123","html_url":"https://github.com/disaster123","followers_url":"https://api.github.com/users/disaster123/followers","following_url":"https://api.github.com/users/disaster123/following{/other_user}","gists_url":"https://api.github.com/users/disaster123/gists{/gist_id}","starred_url":"https://api.github.com/users/disaster123/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/disaster123/subscriptions","organizations_url":"https://api.github.com/users/disaster123/orgs","repos_url":"https://api.github.com/users/disaster123/repos","events_url":"https://api.github.com/users/disaster123/events{/privacy}","received_events_url":"https://api.github.com/users/disaster123/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-07-15T19:04:17Z","updated_at":"2015-07-16T10:56:28Z","closed_at":null,"body":"Currently dm-wb is able to writeback 1,5-2MB/s for totally random 4k i/o by ordering the segments. \r\n\r\nbcache is able to write back with a much higher speed by merging or ordering I/Os sequentially. I think this is possible by keeping a pool of unwritten segments. Currently i work with a permanent pool of 10GB data. So it keeps always 10GB of data on the writeback device and selects then mergable and sequential data to writeback.\r\n\r\nIs something like this possible?\r\n"},"comment":{"url":"https://api.github.com/repos/akiradeveloper/dm-writeboost/issues/comments/121925862","html_url":"https://github.com/akiradeveloper/dm-writeboost/issues/71#issuecomment-121925862","issue_url":"https://api.github.com/repos/akiradeveloper/dm-writeboost/issues/71","id":121925862,"user":{"login":"disaster123","id":861558,"avatar_url":"https://avatars.githubusercontent.com/u/861558?v=3","gravatar_id":"","url":"https://api.github.com/users/disaster123","html_url":"https://github.com/disaster123","followers_url":"https://api.github.com/users/disaster123/followers","following_url":"https://api.github.com/users/disaster123/following{/other_user}","gists_url":"https://api.github.com/users/disaster123/gists{/gist_id}","starred_url":"https://api.github.com/users/disaster123/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/disaster123/subscriptions","organizations_url":"https://api.github.com/users/disaster123/orgs","repos_url":"https://api.github.com/users/disaster123/repos","events_url":"https://api.github.com/users/disaster123/events{/privacy}","received_events_url":"https://api.github.com/users/disaster123/received_events","type":"User","site_admin":false},"created_at":"2015-07-16T10:56:28Z","updated_at":"2015-07-16T10:56:28Z","body":"Yes the bcache code is very complex. That's why i like dm-writeboost. It looks lightweight. Another question Does dm-writeboost not track the written blocks? What happens if i write block A and than read block A but block A is still in the ram buffer or on the caching device. How does dm-writeback knows it has to answer / read the data not from the backing device?"}}