id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host 10498,REGRESSION: vbox 4.1 virtual disk read/write operations are UNUSABLY slow,matteo sisti sette,,"I used to have a Windows 7 guest on a ubuntu 11.10 host with virtualbox 3.x and it worked fine. Then I upgraded to VirtualBox 4.1 on the same host. I recreated an IDENTICAL virtual machine from scratch (because of the infamous broken-3D-driver issue which left me with a broken unrecoverable guest, and none of the method described in the manual and in the forum for fixin it worked) and I installed the same Windows 7 guest OS on it, from the same installation CD as my old guest. Everything is exactly the same as before: same guest, same host, virtual disk in the same physical location, same machine settings, only VirtualBox 4.1 instead of 3.x Now the guest is unusably slow. The bottleneck seems to be reading and writing from/to the vdi. I'm not sure whether it's only writing, only reading, or both, I am under the impression it's mainly writing. Whenever the virtual disk is working, the virtualbox process on the host is consuming 100% CPU, and every disk read/write operation in the guest takes ages. It's simply, plainly unusable. ",defect,closed,other,VirtualBox 4.1.10,obsolete,,,Windows,Linux