Hi, I have approx 800 virtual machines, on a FailoverCluster, connected using FC to a Compellent SAN (50% SAS, 50% SATA). some Windows 2003 R2, some Windows 2008, some Windows 2008 R2, some Windows 2012 and some Windows 2012 R2.
I tried VMs on both Windows Server 2012 and Windows Server 2012 R2.
When I copy a file over an IDE disk, I never go over 90 MB/s. 100 MB/s when copying from the network to the Drive.
When I copy a file over a SCSI disk, I copy between 350 MB/s and 450 MB/s.
If I start a copy over an IDE disk, and, at the same time, I start a copy over a SCSI disk, the copy speed on the IDE drop between 50 MB/s and 75 MB/s, and the SCSI disk copy at 350 MB/s+. Then speed come back on the IDE when the SCSI is over.
If I start two copy on two different IDE disks, the first copy will hang for a couple second when the second copy starts, and I won't go over 70 MB/s on each disk.
The 3 disks are Fixed, and on the same CSV (same LUN). When doing file copy on the HOST, I have the same performance as the SCSI VHDx.
When I create Gen 2 VMs (100% SCSI), they are incredibly more responsive than the Gen 1 (IDE).
How can I fix the IDE performance? Thanks!