[Xen-devel] File System Performance - 10x slower

Nauzad Sadry
2005-01-11T18:30:02Z

Hello all

I am evaluating File I/O performance using Xen & comparing it with
baseline (Fedora Core 3, with 2.6.9 kernel).

Here are the commands that I use for I/O
write I/O:  dd if=/dev/zero of=file1 bs=4K count=256K
read I/O:  dd of=/dev/null if=file1 bs=4K count=256K

Here are some numbers (all test results are reported in MB/second)

Read I/O
- Baseline Fedora Core 3                  - 32
- XEN domain 0                               -  9.3
- XEN domain 1                               - 2.3

Write I/O
- Baseline Fedora Core 3                  - 22
- XEN domain 0                               -  9.8
- XEN domain 1                               - 2.5

- Dom0 (without starting xend) results in 2x slower performance
- DomU results in 9-10x slower performance

I get similar results for domain-1 using both File-based & LVM-based VBD

Can someone why I am getting such huge difference in performance
compared to baseline ??

Thanks

Nauzad