Pengin's questions

We are having trouble with our bonded NICs + vlan + bridged network configuration. We have a blade server running RHEL6, and are trying to set up the networking for KVM virtualisation.

The blade server has 2 NICs (p2p1 and p2p2) which connect to the internal blade chassis 10 Gb switches. We want to bond the 2 blade NICs and setup

1. default vlan (vlan 1) for our production network (172.16.x.x) assigned via DHCP, and
2. vlan 3 on our storage network (192.168.10.x) statically assigned.

There is an added complication that the KVM guests need to connect to our production network, and so we also need a bridge on the production network.

Setting up the bonding (as described here) together with vlan 3 (as described here) seems fine. We used the following configuration files

DEVICE=”p2p1”
BOOTPROTO=”none”
HWADDR=[Removed]
NM_CONTROLLED=”no”
ONBOOT=”yes”
TYPE=”Ethernet”
UUID=[Removed]
MASTER=bond0
SLAVE=yes
USERCTL=no

DEVICE=”p2p2”
BOOTPROTO=”none”
HWADDR=[Removed]
NM_CONTROLLED=”no”
ONBOOT=”yes”
TYPE=”Ethernet”
UUID=[Removed]
MASTER=bond0
SLAVE=yes
USERCTL=no

DEVICE=bond0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no

DEVICE=bond0.3
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.10.22
NETMASK=255.255.255.0
USERCTL=no
VLAN=yes

The problem comes when we try to set up a bridged network connection for the default vlan (vlan 1). For example we might try modifying bond0 and adding br0 as described here.

DEVICE=bond0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
BRIDGE=br0

DEVICE=br0
TYPE=Bridge
BOOTPROTO=dhcp
ONBOOT=yes
DELAY=0

However, br0 never obtains an IP over DHCP. We know it's not a DHCP issues since DHCP works fine if we set it up directly on bond0, but that's not a bridge interface so the VMs can't use it.

How should we configure the interfaces for both vlan 3 (storage) and default vlan for KVM guests and administration?

I've some software that wants access to a very fast disk. I could buy an SSD, but my server has approx 64GB of ram spare. Is it possible to use a portion of that unused RAM to create and mount a virtual disk?

I'm using either Ubuntu or CentOS.

I have a Dell R815 (PDF LINK), which has 6 2.5" bays. I would like to put some Intel X25-E in the spare bays, but have been cautioned that they may not fit since they are SATA and the bays are SAS/proprietary.

On the R815 data sheet it says "Up to Six 2.5” hot-swappable SAS, SATA, or SSD drives".

Can I be sure the X25-E will fit? If not, how am I supposed to use these X25?

When using KVM for virtualisation on Redhat (RHEV), is it possible to live migrate VMs between AMD and Intel boxes? In particular, I'm interested in Opteron 6100 and Intel Xeon 5200 series.

There was an AMD demo in 2008, but I can't find out whether it's now available now or not. On this Red Hat docs page I see no requirement for the same CPU.

My organisation is going to invest in either RedHat virtualization with KVM or VMware ESX. Some of our work involves disk intensive bio-informatics stuff such as BLAST, which we have found to mostly be bottle-necked by the disk rather than the CPU.

I know little about network attached storage, SAN, iSCSI etc., but would appreciate some pointers on which storage technology might be worth focussing on. It seems to me that the fastest solution would be locally attached solid state storage, but then we can't have the advantages of VM migrations for fail-over and load balancing.

What storage solution, for about $6-8k, should we be considering?

I'm investigating options for a small corporate virtualisation setup. We specialise in scientific computing and would like to consolidate our resources. We are keen on KVM, since it looks like it performs well with multiple vCPU per VM.

I'm confused by the RedHat KVM offering. We don't want to virtualise everyone's existing desktops but we do want to have additional virtual desktops, not just ssh access. With "RH Virtualisation for Servers" (much cheaper than the Desktop offering) can we still have the virtual GUI desktops?

I'm setting up a cluster and can wake up individual machines with the command

wakeonlan -i 192.168.1.255 [MAC Address]

I'd like to be able to do this by hostname instead of MAC, but the config file for wakeonlan only seems to offer IP <-> MAC mapping. How can I do it by hostname?

If it helps, I'm running DHCP3 + BIND and have entered all the machines MAC addresses in the dhcpd.conf file so that they get sent the correct hostname when PXEbooting.

Perhaps there is some command like 'host' that would give me a MAC from a hostname?

Thanks