virtualbox.org

Hi,
I use a DELL Latitude with Intel Core I5, 250 Go SSD, 8GO RAM.
The host is Ubuntu 12.04 LTS, with VirtualBox 4.1.12_Ubuntu r77245
The guest is CentOS 6.3, with VboxAdditions 4.1.12_77245

Transferts from a shared folder (on the host) to a CentoS folder (on the vdmk file) is very slow. The transfer speed I get is 6 kb/s.

I did not precisely check the transfer speed in the past but I know it used to be much faster. I currently run a numerical code with data and results in the shared folder and I recently noted that the time need for the same run increased from 1 hour to 13 hours. Just to say to that the decrease in performance is much significant. I guess that some recent upgrade is the cause.

Did someone else observe the same kind of problem ?

All the best,
JMM89

I continue with this post because I could find out what was the reason for the problem.
Everything was slow in fact, not only access to files (which became exceedlingly slow).

For an unknow reason, my Host (Ubuntu) turns to low CPU frequency even when the guest (CentOS) runs a CPU intensive computation. Then I forced the host CPU frequency to its maximum level and could find back the previous performances.

Apparently, the transmission of information regarding the demand or high CPU frequency from guest to host no more exists in the present version of VirtualBox (or may the CPU frequency was always forced to a high value by previous versions of VirtualBox).

Regards,