I/O Performance issue

[decoder_oh]

Hello,


I'm using VirtualBox 1.6 (closed source version) on an AMD64 host running Linux. I created a guest with a VDI hard disk that I converted from a raw dd image and attached it to the virtual SATA controller.

Inside the guest, Linux is also the OS and it perfectly recognizes the disk using AHCI.

However, when I test the read and write speed to the disk, the results are very poor (read with hdparm -t at about 20 mb/s even after the third time...) and write speed at 10-13 mb/s using dd to overwrite an existing file with zeros (I chose an existing huge file that I created before to avoid penalties caused by a possible VDI resizing).

Are there any known issues that lead to such poor I/O performance? If you need additional information, I'll be glad to supply it.


Thanks in advance and best regards,


Chris

[TerryE]

Chris, you might be interested in Kentborg's comments at http://forums.virtualbox.org/viewtopic. ... 7692#27692. It sounds like you are saying the same thing. Interesting. At least the VB guys are tracking this discussion.