Hi Max, Could you try passing msize=262144 for 9p mount point and post the results?
Host: [root@llm116 media]# ls -lhas file 1.1G -rw-r--r-- 1 root root 1.0G Apr 26 11:05 file [root@llm116 media]# dd if=/dev/zero of=file bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 0.700828 s, 1.5 GB/s [root@llm116 media]# time cp file file2 real 0m6.353s user 0m0.007s sys 0m1.520s VM: [root@qemu-img-64 pass]# time cp file 9p_file real 0m12.261s user 0m0.154s sys 0m2.582s [root@qemu-img-64 pass]# dd if=/dev/zero of=file.9 bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 2.07335 s, 518 MB/s [root@qemu-img-64 pass]# mount [snip] v_pass on /pass type 9p (rw,trans=virtio,version=9p2000.L,msize=262144) [/snip] -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/965867 Title: 9p virtual file system on qemu slow Status in QEMU: New Status in “qemu-kvm” package in Ubuntu: Confirmed Bug description: Hi, The 9p virtual file system is slow. Several examples below: --------------------------------------------------------- Host for the first time: $ time ls bam.unsorted/ ........................... real 0m0.084s user 0m0.000s sys 0m0.028s -------------------------------------------------- Host second and following: real 0m0.009s user 0m0.000s sys 0m0.008s ------------------------------------------------------ VM for the first time: $ time ls bam.unsorted/ ................................ real 0m23.141s user 0m0.064s sys 0m2.156s ------------------------------------------------------ VM for the second time real 0m3.643s user 0m0.024s sys 0m0.424s ---------------------------------------------------- Copy on host: $ time cp 5173T.root.bak test.tmp real 0m30.346s user 0m0.004s sys 0m5.324s $ ls -lahs test.tmp 2.7G -rw------- 1 oneadmin cloud 2.7G Mar 26 21:47 test.tmp --------------------------------------------------- $ copy on VM for the same file time cp 5173T.root.bak test.tmp real 5m46.978s user 0m0.352s sys 1m38.962s To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/965867/+subscriptions