• Read the Windows setup page and the Windows x64 setup page (if you are on 64 bit)

If you are on a 64 bit Windows install:

• Check out this post if your JRuby is using the 32 bit JVM on a x64 Windows setup
• You need to use version 4.0 of VirtualBox (rather than the latest). You can get it from here
• You need to use an older version of Vagrant:

  jgem install jruby-openssl jruby-win32ole
  jgem install --version '=0.7.8' vagrant

• If the vagrant box download stops around 4G, check that you have a NTFS filesystem (rather than FAT) and deactivate any "network" scanning capabilities of installed security software (I had problems with NOD32 particularly)

HTH

1. Remove the HWADDR line from /etc/sysconfig/network-scripts/ifcfg/eth0
2. Delete the file /etc/udev/rules.d/70-persistent-net.rules (hat tip)

These two steps are specific to CentOS 6 (on 5.x the first step is sufficient). Also, the second if is recreated at the next boot, thus after rm-ing it, you should shut down the machine and package it (not start it again, or if you do, you should remove the file again).

Via run-virtual.com.

• This is a good general OpenBSD tutorial
• If you get the following message with OpenBSD:

  uid 0 on /: file system full
  /: write failed, file system is full
  Segmentation fault

  The solution described by this VB ticket might help you. Specifically you need run the machine from the command line with the -noraw0 switch.

• For FreeBSD choose the PCne-PCI II network card (instead of III) and 10BaseT as your media type if you want your networking to work
• A quick starter for NetBSD: it fails to ping the DNS server in NAT mode (10.0.2.3), but the network still works, so you can go ahead with the install.

• Don’t have writable shares on the network the virtual machine is connected to. If you want to share a directory to extract file, share it from the client OS and copy it from outside
• If possible put it on a different subnet
• Use non-persistent hard disks or snapshots and revert to them regularly (currently the only commercial grade product that I know of that can do this is VMWare. QEmu also has this feature, but unfortunately it still needs some time to become a stable solution)

Following these rules you get a more secure and more convenient system than using a separate PC with something like DeepFreeze, but you loose the ability to stay logged on sites (because you loose all your cookies, history and cache).

Finally, I’m getting in synch with the released episodes. This one is relatively error-free, I have only just a few comments to make:

buffer overrun doesn’t always mean that the buffer is on the stack, it can be in the heap also. Hardware DEP prevents both kind from executing code.

Leo probably meant to say turn it on for essential Windows programs and services only instead of turn it off …

This episode is the first in which I hear Steve correcting itself, so I think this is worthy of quoting: Remember that I said last week that one of the major failings of Server was that it lacked both sound and USB support. Well, that was wrong.

They support every flavor of Linux you can imagine – FreeBSD, OS/2 Warp, Sun’s Solaris – OS/2 Warp isn’t a flavor of Linux by a long shot, but I give him the benefit of the doubt because probably he was meaning every kind of OS.

The only real problem in this podcast (netcast, sorry) is the discussion about the fixed size versus expandable drives. The state of the matter is the following: when you choose to use disks for which the space is not preallocated it saves in the file only the parts of the disk which were written too (because if the guest OS tries to read from any other area, it can just return zeros). There are two problems with this (lumped together by Steve under the name fragmentation): these disk areas are stored in a non-contiguous mode in the file, so at every access a lookup step is necessary and also there is the fact that as the file grows it itself can be fragmented on the disk. A third problem is that these files are never able to shrink. The explanation for this is the fact that the virtual machines don’t know about file systems, only about disk sectors. When a sector has been written too, it is marked as dirty and stored permanently in the file, even if the file occupying that space has been deleted. Given all this things I don’t think that Parallels’s product which probably only goes through the file system and marks the empty disk sectors is worth its price. It would be a nice extra if it was included in the program, but not as a stand-alone product.