2017-02-22 17:36 GMT+08:00 Kevin Wolf <[email protected]>: > Am 22.02.2017 um 10:29 hat Jaze Lee geschrieben: >> 2017-02-22 17:17 GMT+08:00 Kevin Wolf <[email protected]>: >> > Am 22.02.2017 um 10:05 hat Jaze Lee geschrieben: >> >> I test on cache=none with sata disk, because i do not have ssd in my pc, >> >> and I do not find any performance improved. >> >> >> >> I do not know why the performance is not be improved.... >> > >> > Most likely your disk is just too slow for the memory copy to make any >> > significant difference, and the memcpy cost is dwarved by the actual >> > disk I/O cost. >> > >> > Have you tried backing the server with a ramdisk instead? >> >> No yet... >> >> Do you mean I should use ramdisk as the root disk of the vm? >> then attach the rbd volume to it? > > Did you intentionally drop the mailing list CC?
Sorry, it is not intentional..... > > No, the VM should just directly use rbd as it used to. It's the rbd > server that should operate on a ramdisk rather than your SATA disk, > so that you get any physical disk out of the way (because physical > disks, and even more so spinning rust, make things slow). Oh, I think i should change to another host, with large memory.... Thank you. > > Kevin -- 谦谦君子
