XenServer IDE performance issue – Resolved
As I said in my previous post after setting up XenServer I had problems with horrible perfomance using an IDE drive. After investigating I found it was because the OS was using a generic ide driver. Because of this you could not turn DMA/UDMA on for the drive which resulted in pathetic read/write times.
/dev/hdd:
multcount = 16 (on)
IO_support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)
geometry = 19457/255/63, sectors = 312581808, start = 0
I found an article related to previous versions of XenServer that detailed how to modify the boot loader to get a workaround for the problem. However, it appears in XenServer 5 the was changed and I was unable to get this to work in the updated location. For those who are looking it is under /boot/ and the conf file is extlinux.conf.
After trying a lot of different things I finally had to rebuild the initrd image file that is used in the boot loader to include the specific driver for my controller. In my case this was an ATI controller.
Once I did that I could then enable DMA and performance was not an issue after that.
February 7th, 2009 - 16:10
Hello,
I have the same Problem with mei XenServer5.
Would be really great if you could give me a detailed description what you did to solve your performance problems?
thanks in advance.
best regards,
Walter
March 30th, 2009 - 16:03
Hi,
I too have the same problem and need a fix. Is there any change you could post details of how you fixed this? I have looked everywhere and have had no luck. I even posted on the citrix forum (and bumped the post once already) and not a single person has responded.
Thanks,
Anthony.
March 30th, 2009 - 18:11
@Anthony
You know, I had documented what I did to resolve the issue (in detail) but I can’t seem to find my notes.
I’m currently running through the steps again to try and give you both a way to complete this. I can tell you off memory what was happening is upon boot the generic IDE driver was taking control before my ATI driver for the IDE controller could.
Again, I will do my best to get together a quick and dirty guide.
March 30th, 2009 - 19:47
@Nick Holmquist
Check the following thread:
http://forums.citrix.com/thread.jspa?threadID=150391
At the bottom you will find a mkinitrd command. I had to first use dmesg to find where the generic IDE module loaded and therefore my ATI module for my controller could not.
I found the proper module name for my controller and created a new initrd file which I called from extlinux.conf