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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:
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| Code Block | ||
|---|---|---|
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# 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
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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.
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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:
| Code Block |
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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:
| Code Block |
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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 a are quite some vm modules loaded:
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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".