Louise Hoffman's questions

None of the Nagios DHCP check plugins can actually take an IP from the DHCP server as a real test. All they do is ask which IP it would give to a certain mac address.

Our DHCP server failed, where Nagios didn't alert, because it could pass the Nagios test, but not actually give the IP to clients.

Question

Is there a way for a script request an IP and have the DHCP server deliver it? The script would run every 5 minutes, so it would throw away the IP at every run.

Update

Ideally what the script should do is

# dhclient -r ; dhclient ; ip a|grep valid_lft
Killed old client process
       valid_lft forever preferred_lft forever
       valid_lft forever preferred_lft forever
       valid_lft 86459sec preferred_lft 86459sec
       valid_lft forever preferred_lft forever

and if preferred_lft isn't renewed, then alert.

The problem which this method is requires a dedicated NIC for for this. So it would be really good, if this could be simulated somehow?

Is it safe to replicate from a Solaris 10 ZFS v22 to a FreeBSD 8.3 ZFS v28?

Are there someone that have done this with specific versions of ZFS, where it worked perfectly?

I would like to try out Oracle VM just for fun.

Can it be downloaded for free from Oracle?

And if so, does anyone have a link?

When I look at "man virt-install" for Fedora 13 I see

  --virt-type
    The hypervisor to install on. Example choices are kvm, qemu, xen, or kqemu.
    Availabile options are listed via 'virsh capabilities'
    in the <domain> tags.

But which should I use for which guest OS?

My host is a Fedora 13 with KVM.

Using CentOS 5 with KVM.

I have downloaded this KVM applicance, and when unzipped it is just a .img file. No xml file supplied.

I can start the guest with

 /usr/libexec/qemu-kvm -hda /data/kvm/slash.img -m 512

and it works.

Now I would like to make a config file for the guest.

The problem is when I do

# virsh -c qemu:///system list
 Id Name                 State
----------------------------------

# 

I don't see the guest as expected.

Does anyone know what is wrong?

From my understanding the networks is as follows

Class A: 10.0.0.1 - 10.255.255.254
Class B: 172.16.0.1 - 172.16.255.254
Class C: 192.168.0.1 - 192.168.0.254

But then I look at ifconfig virbr0 on my Linux computer:

virbr0    Link encap:Ethernet  HWaddr 42:40:99:CB:02:7F  
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:2842 (2.7 KiB)

Here the IP address is 192.168.122.1. Is that an allowed IP?

And if so, is 192.168 than actually a Class B network?

Can someone tell me if this is a High Performance Compute or High Available mySQL cluster?

There is a picture of the setup.

This is part of the config.ini they talk about

[ndbd default]
NoOfReplicas=2    # Number of replicas

Is it correct understood that NoOfReplicas determines if I have a HPC or a HA cluster?

Does anyone know of a good program, web service, or CMS for documenting servers, IP addresses, logins, and network?

Only requirement it must run on and from Linux.

And it is just for a small network of 10-15 servers.

Is it possible to have both a class A and a class B network on the same switch?