Prelude^

This time, i will not use my desktop pc, but my new server which happens to be in the office. Here are the hardware specs:

• CPU: 2x E5605 Westmere
• RAM: 24GB
• Raid: HW (Adaptec Z 5xxx), write cache enabled
• Storage: Raid1 2xSAS 10k (root) | Raid10, 10x SAS 10k (databases)

Software:

• Debian 6.0 Squeeze
• Linux 2.6.32
• XEN 4.0.1 | KVM 0.12.4
• MySQL 5.1.48
• Apache 2.2.16
• sysbench 0.4.12

Virtual machine specs:

• 2GB RAM
• 2 VCPUs
• 10GB HDD root
• 10GB HDD database

Each virtual container will get 2GB RAM and 2 virtual CPUs.

Tests^

MySQL^

The sysbench commandline looks kind of following:

#> time sysbench --num-threads=2 --max-requests=100000 --test=oltp  --oltp-table-size=1000000 --mysql-host=HOST --mysql-db=DB  --mysql-user=USER --mysql-password=PASS run

The tests ran with varying amount of threads. The resulting values are an average over three test-runs. The “Operations” are summarized I transactions, read/write requests and other operations (see sysbench results).

The sysbench results can be downloaded here for XEN and here for KVM.

Besides the break with 2 threads, XEN seems to be 10% to 15% faster then KVM.

Apache static^

In those tests, i used ab to call the default static “it works” page from apache 1000 times with varied concurrency.

XEN benchmarks, KVM benchmarks

Those results are interesting. XEN does start very strong, but KVM seems to handle concurrent requests very well. In the end, XEN’s performance decreases with 100 concurrent requests, where KVM still is able to improve performance. I think KVM is the winner here.

Apache + MySQL: WordPress^

So, XEN seems to outperform in KVM in the MySQL benchmark, whereas KVM wins clearly in the Apache tests. This scenario should be a more “real world”. For testing, i’ve installed a fresh WordPress 3.0 with just enough setup to deliver the “Hello World” page. Again, i’ve used ab to execute the tests.

XEN benchmarks, KVM benchmarks

As it seems, the stronger limiting factor seems to be the mysql performance.

Results^

I will probably stick to XEN for some more time. It proved itself of being stable and with the new 4.x also very fast.