Question : IBM X3200 with LSI RAID, slow disk performance in Hyper-V virtual machine ?

I have Ibm X3200, with RAID 1 on disk 1+2
Host OS (server 2008 with hyper-v) are installed on RAID disks.
VHD file are 60GB, and fixed size. In virtual machine are installed Server 2008.
Problem is that copy on virtual machine on same disk, from one folder to another folder is slow, only 5-6 MB/sec , but if copy from this disk to another disk than is ok speed (40-60 MB/sec).
I suspect that is problem in RAID controller because if VHD file is on disk that is not configured as RAID, speed is ok.

Answer : IBM X3200 with LSI RAID, slow disk performance in Hyper-V virtual machine ?

hmm,

It could be that its very slow for a few reasons:

1, the RAID controller might have a smaller cache and can't handle the I/O operations with this kind of setup.

2, Since you have 1 logical disk running RAID 1 (slower performance than other RAIDs like 5), and your VHD sits on this same disk, That would be the same as doing a file copy within the same volume - there is only 1 disk read/write head so copying data will be much slower as its running the machine and its processes and performing a copy, forcing a lot of I/O to a "single" disk (as far as hyper-v is concerned).