Hi all! I'm using an OpenBSD VM with qemu-kvm 0.12.5 (Debian repositories) and Linux 2.6.34.5 compiled with the kernel.org sources. I'm seeing a important difference in the bandwidth when I make a transfer to or from a OpenBSD VM. Here are some results: bsd:~# iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 4] local 10.1.0.43 port 5001 connected with 10.1.0.65 port 55049 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 25.2 MBytes 21.1 Mbits/sec [ 4] local 10.1.0.43 port 5001 connected with 10.1.0.65 port 55050 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 25.3 MBytes 21.2 Mbits/sec [ 4] local 10.1.0.43 port 5001 connected with 10.1.0.65 port 55051 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 24.5 MBytes 20.5 Mbits/sec [ 4] local 10.1.0.43 port 5001 connected with 10.1.0.65 port 55054 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 24.1 MBytes 20.2 Mbits/sec [ 4] local 10.1.0.43 port 5001 connected with 10.1.0.65 port 55055 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 26.5 MBytes 22.2 Mbits/sec [ 4] local 10.1.0.43 port 5001 connected with 10.1.0.65 port 55057 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 28.9 MBytes 24.2 Mbits/sec I also did some tests with scp, presenting a "stalled" state at various times of the transfer: ss01:/usr/src# scp linux-2.6.34.5.tar.bz2 viper@bsd:/tmp/ viper@bsd's password: linux-2.6.34.5.tar.bz2 100% 65MB 1.3MB/s 00:51 Another test: ss01:/usr/src# cat linux-2.6.34.5.tar.bz2 | nc -l -p 2222 -q 0 bsd:~# nc ss01 2222 | pv | dd of=/dev/null 64.5MB 0:00:48 [1.32MB/s] [ <=> ] 132161+1 records in 132161+1 records out 67666495 bytes transferred in 48.766 secs (1387557 bytes/sec) Using the same test on a Debian GNU/Linux VM: debian-test2:~# iperf -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 10.1.0.45 port 5001 connected with 10.1.0.65 port 42905 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.1 sec 111 MBytes 92.1 Mbits/sec [ 5] local 10.1.0.45 port 5001 connected with 10.1.0.65 port 42906 [ 5] 0.0-10.0 sec 110 MBytes 92.0 Mbits/sec [ 4] local 10.1.0.45 port 5001 connected with 10.1.0.65 port 42907 [ 4] 0.0-10.1 sec 110 MBytes 91.6 Mbits/sec [ 5] local 10.1.0.45 port 5001 connected with 10.1.0.65 port 42908 [ 5] 0.0-10.0 sec 106 MBytes 88.4 Mbits/sec [ 4] local 10.1.0.45 port 5001 connected with 10.1.0.65 port 42909 [ 4] 0.0-10.0 sec 109 MBytes 91.0 Mbits/sec [ 5] local 10.1.0.45 port 5001 connected with 10.1.0.65 port 42910 [ 5] 0.0-10.0 sec 107 MBytes 89.4 Mbits/sec ---------------------------------------------------------------------- ss01:/usr/src# scp linux-2.6.34.5.tar.bz2 root@debian-test2:/tmp/ root@debian-test2's password: linux-2.6.34.5.tar.bz2 100% 65MB 12.9MB/s 00:05 ---------------------------------------------------------------------- ss01:/usr/src# cat linux-2.6.34.5.tar.bz2 | nc -l -p 2222 -q 0 debian-test2:~# nc ss01 2222 | pv | dd of=/dev/null 64,5MB 0:00:04 [14,9MB/s] [ <=> ] 132161+1 records in 132161+1 records out 67666495 bytes (68 MB) copied, 4,3326 s, 15,6 MB/s In Debian virtual machines I use Virtio (disk only). But this substantial difference may be due to the use of Virtio or another reason? The network interface I'm using OpenBSD is a e1000. The network interface used in Debian virtual machine is a Realtek. Thanks in advance for your reply. Regards, Daniel -- Fingerprint: BFB3 08D6 B4D1 31B2 72B9 29CE 6696 BF1B 14E6 1D37 Powered by Debian GNU/Linux Lenny - Linux user #188.598
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