I have a system who's normal activity is running Xen 3.3.1 with Centos 5.3 as the DomU. I had reason to connect an IDE drive to the single IDE interface that this board has. I was getting slow performance. hdparm -t revealed that the thoughput was down to just 2.7 MB/sec. After some tweaking (switch on 32 bit,etc) and retesting under a non-Xen config, I managed to get that to 8MB/Sec. When I move the drive to a USB to IDE adapter, hdparm -t gives me about 18MB/Sec. Big improvement, although I don't know if it is then perfect..
My kernel is 2.6.18-128.4.1.el5. I have kernel parameter pci=nomsi. I can't remember exactly why I needed this, but there was a good reason, maybe SATA drive not working properly or some such. Could this be the cause of my issue?
The motherboard blurb states that the IDE interface is ATA/133 compliant and I am using the provided IDE cable. I have tried three hard disks, all with similar results. (2x 40gb + 1x 160gb)
lspci | grep IDE gives
00:06.0 IDE interface: nVidia Corporation MCP78S [GeForce 8200] IDE (rev a1)
As a reference, hdparm -t against the SATA drive in AHCI mode on the same board gives about 110MB/Sec.
Any ideas, anyone?
Thanks in advance,
Ian.
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