First off, let me give you the specs on the server. It is a 5 year old HP server with a hardware RAID controller set up with one logical drive in RAID 5 configuration (three 72gb 15k rpm drives and a hot spare). Windows Server 2003 Standard is installed to C and the data partition is D. The server has an HP Ultrium 1 drive driven by Symantec Backup Exec 11. I was backing up 116gb nightly to the tape drive in about 5.5 hours and I was getting 600mb/min or so tranfer rate.
The data partition(D) was getting really low on disk space, so we bought two more 72gb 15k rpm drives from HP and installed them to the server. In the HP Array Management utility, we made the two drives part of the existing array and extended the logical drive. It took a half day or so while the array extended itself. Once that was complete, I could see in Windows 2003 disk management that there was additional unallocated space. I converted the disk to dynamic so I could extend D onto the new space. I have attached an image of how the disks look in disk management to that point.
After doing this, things seemed fine until I got to looking at backups. After doing all of this and having the same 116 GB of data on the server, the transfer rate has cut down to as low as 92mb/min and only as high as 235mb/min. This resulted in a backup taking 10.5+ hours rather than 5 before. The server doesn’t really seem to be suffering performance wise.
I didn’t really see this as a chance coincidence, but I updated the tape drive drivers and array controller drivers and that didn’t change a thing. I am feeling that it has to be the fact that the single logical drive is a dynamic disk in Windows 2003. Why would this be? Part of me now wonders if I should have just left it a basic disk, backed up D after putting the new drives in and then delete the D partition. I could have then recreated D using the entire unallocated space and had a clean basic disk with two partitions. I didn’t think of this until now and I would have been reluctant to try it since I hate relying on a backup (or even two) when deleting a partition altogether. The data is extremely mission critical.
Of course the OS is on the dynamic disk, so I can’t convert back to basic and try it. Does anyone think I am just stuck now and could changing to dynamic disk have hurt my backup performance that much? What can I do now?