One of possible problems could be a block size. In this case I am using ZFS with raidZ 4+1 drives. Each drive has 4Kb block. So optimal block size is 16384 bytes. By optimizing block size it possible to improve performance 10 folds but 9p stably provides 10 folds worse performance than native writes.
Some extra tests: --------------------- VM - mapped $ dd if=/dev/zero of=test count=100000 100000+0 records in 100000+0 records out 51200000 bytes (51 MB) copied, 20.7879 s, 2.5 MB/s $ dd if=/dev/zero of=test count=100000 bs=16384 100000+0 records in 100000+0 records out 1638400000 bytes (1.6 GB) copied, 74.4378 s, 22.0 MB/s ------------------------------------------------------------ Host: $ dd if=/dev/zero of=test count=100000 100000+0 records in 100000+0 records out 51200000 bytes (51 MB) copied, 1.60118 s, 32.0 MB/s $ dd if=/dev/zero of=test count=100000 bs=16384 100000+0 records in 100000+0 records out 1638400000 bytes (1.6 GB) copied, 4.89932 s, 334 MB/s Iggy: I has issue with permission in passthrough mode. Can you give an idea how to setup permissions in this mode? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/965867 Title: 9p virtual file system on qemu slow To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/965867/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
