Comparison between Xen and VMWare

Disk performance

Xen

The test is done over /root, where the disk is a logical volume specially for the virtual machine. Raid1 over two disks is behind.

Dec 06 13:34 [root@pub:~]# dd if=/dev/zero of=/root/thing bs=1024 count=1024k
1048576+0 records in
1048576+0 records out
1073741824 bytes (1.1 GB) copied, 12.9547 seconds, 82.9 MB/s

Dec 06 11:55 [root@pub:~]# bonnie++ -u root -s 7000 -r 0 -b -d /root/
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
pub.lcg.cscs. 7000M   451  98 53494  11 29537   1   807  66 94265   2 257.5   0
Latency             23957us    2261ms    2977ms     648ms    1330ms    1754ms
Version  1.96       ------Sequential Create------ --------Random Create--------
pub.lcg.cscs.ch     -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16    55   0 +++++ +++    61   0    65   0 +++++ +++    64   0
Latency              6000ms     499us    3115ms    2426ms      15us    3305ms

Dec 06 14:08 [root@pub:~]# dd if=/root/thing of=/dev/null
2097152+0 records in
2097152+0 records out
1073741824 bytes (1.1 GB) copied, 9.39562 seconds, 114 MB/s

VMWare

The test is done over /root, where the disk is a file on the host's filesystem. Raid1 over two disks is behind.

[root@ppwn01 ~]# dd if=/dev/zero of=/root/thing bs=1024 count=1024k
1048576+0 records in
1048576+0 records out
1073741824 bytes (1.1 GB) copied, 9.29409 seconds, 116 MB/s

[root@ppwn01 ~]# bonnie++ -u root -s 5000 -r 0 -b -d /root/
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
ppwn01.lcg.cs 5000M  1208  91 17624   3 49144   3  3918  95 113098   5 368.3   2
Latency              6520us    6915ms     287ms    8979us   41605us     120ms
Version  1.96       ------Sequential Create------ --------Random Create--------
ppwn01.lcg.cscs.ch  -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16    80   0 +++++ +++    80   0    80   0 +++++ +++    80   0
Latency               137ms     498us   84625us     149ms      16us   89699us

[root@ppwn01 ~]# dd if=/root/thing of=/dev/null
2097152+0 records in
2097152+0 records out
1073741824 bytes (1.1 GB) copied, 9.67018 seconds, 111 MB/s

Compile kernel

Xen

Dec 06 13:28 [root@pub:~]# time tar -xf linux-2.6.36.1.tar 
real    0m33.963s
user    0m0.124s
sys     0m1.600s

Dec 06 13:39 [root@pub:linux-2.6.36.1]# make defconfig
Dec 06 13:39 [root@pub:linux-2.6.36.1]# time make
[...]
real    10m11.454s
user    6m28.432s
sys     2m12.040s

VMWare

[root@ppwn01 ~]# time tar -xf linux-2.6.36.1.tar 
real    0m14.374s
user    0m0.113s
sys     0m1.707s

[root@ppwn01 linux-2.6.36.1]# make defconfig
[root@ppwn01 linux-2.6.36.1]# time make
[...]
real    9m41.033s
user    6m59.439s
sys     2m39.054s

HEPSPEC06

Xen

SPEC2006 results for pub.lcg.cscs.ch: 11.65

VMWare

SPEC2006 results for pub.lcg.cscs.ch: 11.60

Network

Xen

Dec 07 09:10 [root@pub:~]# iperf -c 148.187.66.232
------------------------------------------------------------
Client connecting to 148.187.66.232, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 148.187.66.50 port 58274 connected with 148.187.66.232 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.11 GBytes    951 Mbits/sec

VMWare

[root@ppwn01 ~]# ./iperf -c 148.187.70.232
------------------------------------------------------------
Client connecting to 148.187.70.232, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 148.187.68.201 port 51597 connected with 148.187.70.232 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  2.20 GBytes  1.89 Gbits/sec

Conclusions

CPU power is the same. The differences are within IO
Network performance is much better in VMWare, reaching up to 4 Gbit/s, because it uses infiniband
Bulk disk performance is also better in VMWare, but exceeds in small disk operations by at least a factor of 2 in some cases.
Monitoring in VMWare is also better, there are very nice graphs in the GUI,
VMWare's GUI needs Windows installed and is the only way to manage/create the virtual machines. Clumsy.