Getting ready for the new Ubuntu LTS release 
It looks good, and it feels fast. Rebooting a VM takes 9 seconds, which is faster than ever. No need to schedule maintenance windows any more (not that I did anyway 
).
Network interface configuration and DNS resolution
Things have changed. Both interface configuration and name resolution configuration are now done in /etc/network/interfaces. There is a new flag for autoconfiguration, so no need to echo things to /proc anymore. For our dual stack staticly configured servers the configuration looks like this:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 inet static
address 192.87.30.54
netmask 255.255.255.192
gateway 192.87.30.1
# This is a statically configured IPv6 interface
iface eth0 inet6 static
autoconf 0
privext 0
address 2001:610:148:dead::54
gateway 2001:610:148:dead::1
netmask 64
accept_ra 0
dns-search terena.org
dns-domain terena.org
dns-nameservers 2001:610:1:800a:192:87:106:106 2001:610:188:140:145:100:188:188
Note that despite the comment on the second line (see interfaces(5)), not everything is explained there. You have to look at resolvconf(8) as well: all the options that used to be available to resolv.conf, can be put in interfaces, if you prefix them with "dns-". Take care that instead of configuring multiple nameserver-lines, they are now on one dns-nameservers line.
There is a bug that effectively overrides the privext value with what's in /etc/sysctl.d/10-ipv6-privacy.conf. You have to work around it by commenting out the two lines there.
VMware tools
Our setup consists of VMware ESXi 4.1 boxes, and I configured the Precise VMs with a vmxnet3 NIC, and a paravirtualised SCSI hard disk, and the linux-image-virtual kernel.
When it comes to the VMware tools, there are a few options:
1 - Do nothing
This is the simplest approach, and usually my favourite. A freshly installed VM will load a number of VMware modules that apparently are part of the 3.2 kernel these days:
[ 2.135796] VMware PVSCSI driver - version 1.0.1.0-k [ 2.136064] vmw_pvscsi 0000:03:00.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18 [ 2.136279] vmw_pvscsi: using 64bit dma [ 2.136688] VMware vmxnet3 virtual NIC driver - version 1.1.29.0-k-NAPI [ 2.137030] vmxnet3 0000:0b:00.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19 [ 2.137217] vmxnet3 0000:0b:00.0: setting latency timer to 64 [ 2.201568] vmxnet3 0000:0b:00.0: (unregistered net_device): features: sg csum vlan jf tso tsoIPv6 lro highDMA [ 2.202810] vmxnet3 0000:0b:00.0: irq 72 for MSI/MSI-X [ 2.202837] vmxnet3 0000:0b:00.0: irq 73 for MSI/MSI-X [ 2.202863] vmxnet3 0000:0b:00.0: irq 74 for MSI/MSI-X [ 2.202890] vmxnet3 0000:0b:00.0: irq 75 for MSI/MSI-X [ 2.202916] vmxnet3 0000:0b:00.0: irq 76 for MSI/MSI-X [ 2.203752] vmw_pvscsi 0000:03:00.0: setting latency timer to 64 [ 2.205264] vmw_pvscsi 0000:03:00.0: irq 77 for MSI/MSI-X [ 2.205322] vmw_pvscsi: using MSI-X [ 2.205497] scsi2 : VMware PVSCSI storage adapter rev 2, req/cmp/msg rings: 8/8/1 pages, cmd_per_lun=64 [ 2.205775] vmw_pvscsi 0000:03:00.0: VMware PVSCSI rev 2 host #2 [ 2.206296] scsi 2:0:0:0: Direct-Access VMware Virtual disk 1.0 PQ: 0 ANSI: 2
Also, it will load the vmw_balloon module.
I'd say all of this is an improvement over the "do nothing" approach in Lucid, because back then no specific VMware modules would be loaded at all. But now, VCenter still displays "Not installed" as the VMware Tools status...
2 - Distro provided OpenVM-tools
This is slightly more work than the "do nothing" scenario, but it's very easy because everything sits in the Ubuntu repository. To install the OpenVM-tools on a server be sure to leave out the recommended packages, so that you don't end up with tons of unnecessary X-server packages:
apt-get install --no-install-recommends linux-headers-virtual open-vm-dkms open-vm-tools
The open-vm-dkms package takes care of automatically rebuilding modules whenever there is a kernel upgrade. You can see this in action when installing it:
Setting up open-vm-dkms (2011.12.20-562307-0ubuntu1) ... Loading new open-vm-tools-2011.12.20 DKMS files... First Installation: checking all kernels... Building only for 3.2.0-23-virtual Building for architecture x86_64 Building initial module for 3.2.0-23-virtual Done.
After this there are quite some vm modules loaded:
root@precise:~# lsmod | grep vm vmxnet 26931 0 vmblock 18757 0 vmsync 13024 0 vmhgfs 63406 0 vmci 97231 1 vmhgfs vmw_balloon 12809 0 vmw_pvscsi 22881 1 vmxnet3 45922 0
VCenter now says the VMware Tools status is "Unmanaged" - slightly better than nothing.
3 - VMware provided tools
This is the most work, but it's not too hard.
It basically comes down to:
- in vSphere client: right-click Guest -> Install/Upgrade VMware tools
- In the guest:
mount /dev/cdrom /media/cdrom, then extract the tar.gz - Install the tools using
vmware-install.pl --default
I will run some test to see which scenarios allow VCB to make backups.
/sbin/halt doesn't power off any more
This bug functionality change appears to have been introduced in 11.10, but because I only use LTS I didn't find out until now.
Easy workaround: issue "halt -p".