Performance issues with KVM - Redhat

The general performance issue with KVM is due to DISK I/O

- by default the Redhat KVM guest are created with x86_64 architecuture, if you installed 32 bit operating system change this to i686.

<os>
<type arch='i686' machine='rhel5.6.0'>hvm</type>
<boot dev='hd'/>

- Make sure the hypervisor used is correct in the configuration , either qemu or kvm

<domain type='kvm'>

or

<domain type='kvm'>

- Use virtio drivers if the guest is paravirtulized (http://www.ibm.com/developerworks/linux/library/l-virtio/index.html?ca=dgr-lnxw97Viriodth-LX&S_TACT=105AGX59&S_CMP=grlnxw97 ,  http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=/liaat/liaatbpparavirt.htm)

./arun

yum update, IndexError: tuple index out of range

If you happen to get this error while updating server with yum update
--
.
.
.
File "/usr/lib/python2.4/site-packages/M2Crypto/m2urllib2.py", line 82, in https_open
h.request(req.get_method(), req.get_selector(), req.data, headers)
File "/usr/lib/python2.4/httplib.py", line 813, in request
if v[0] != 32 or not self.auto_open:
IndexError: tuple index out of range
--
disable the location aware access from rhn.

Ref:
http://kbase.redhat.com/faq/docs/DOC-16881

./arun