virtualbox.org

Hi folks,
I'm just wondering if there's a way to speed up vdi copy on windows host. Right now, on a fairly standart computer (sata disk), it takes nearly half an hour to copy a 5GB dynamic disk :-/

I guess that i'm doing something wrong but dunno what

The basic idea is too clone a master vdi (read only mode) file in order to use the clone for testing purpose...


Thanks.

Check your drive for errors. Is there enough free space left on the destination partition and isn't the free space heavily fragmented? How fast can you write other files to it? What did you use to copy the vdi?

With a modern PC you should get 20Mb/sec I/O rate to a spindle minimum. Modern SATA disks will do double this so this size of copy should less than 8 mins. For it taking 30 mins, you must either have a really old ATA disk over IDE33 or your files system is fragmented to hell and therefore the copy involves a high frequency of disk seeks. Unfortunately defragmenting a badly fragmented NTFS volume is difficult with the standard Windows told, especially if the volume is over 75% full. One of the problems with the standard MS utility is that if you have a big file (such as a VDI) in a few hundred fragments then it won't move it unless there is a contiguous gap to fit in in. You could also try the Sysinternals contig tool.

Thanks guys, will check all those things first ! This isn't a hardware issue as i've tested on several boxes with sata hard drives

Thanks !

If you have a virus scanner or anti-spyware scanner, try disabling the on access scan, as it can also slow the copying of large files.