Monthly Archives: September 2012

Converting Xen Linux VMs to VMWare

A year ago I wrote about how to convert from Xen to VMWare (which is a similar process to a Xen virtual-to-physical or V2P conversion). Now I found a much simpler solution, thanks to .

In this example, I’m using LVM disks, but the process is no different from using Xen disk images.

  1. Install Debian Wheezy into a VMWare virtual machine. Attach a secondary virtual disk (it will be called /dev/sdc from now on) that’s sized about 500 MB larger than your Xen DomU (just to be safe). Fire up the VM. All subsequent commands will be run from inside that VM.
  2. Check whether your DomU disk has a partition table: ssh root@xen fdisk -l /dev/xenvg/4f89402b-8587-4139-8447-1da6d0571733.disk0. If it does, proceed to step 3. If it does not, proceed to step 4.
  3. Clone the Xen DomU onto the secondary virtual disk via SSH: ssh root@xen dd bs=1048576 if=/dev/xenvg/4f89402b-8587-4139-8447-1da6d0571733.disk0 | dd bs=1048576 of=/dev/sdc. Proceed to step 7.
  4. Zero out the beginning of the target disk: dd if=/dev/zero of=/dev/sdc bs=1048576 count=16
  5. Partition it and add a primary partition 8 MB into the disk: fdisk /dev/sdc, o Enter w Enter, fdisk /dev/sdc, n Enter p Enter 1 Enter 16384 Enter Enter, w Enter
  6. Clone the Xen DomU onto the secondary virtual disk’s first partition via SSH: ssh root@lara dd bs=1048576 if=/dev/xenvg/4f89402b-8587-4139-8447-1da6d0571733.disk0 | dd bs=1048576 of=/dev/sdc1
  7. reboot
  8. Mount the disk: mount -t ext3 /dev/sdc1 /mnt; cd /mnt
  9. Fix fstab: nano etc/fstab: change root disk from to /dev/sda1
  10. Fix the virtual console: nano etc/inittab: replace hvc0 with tty1
  11. Chroot into the disk: mount -t proc none /mnt/proc; mount -t sysfs none /mnt/sys; mount -o bind /dev /mnt/dev; chroot /mnt /bin/bash
  12. Fix mtab so the Grub installer works: grep -v rootfs /proc/mounts > /etc/mtab
  13. Install Grub: apt-get install grub2. When the installer asks to which disks to install, deselect all disks.
  14. Install Grub to MBR: grub-install –force /dev/sdc
  15. Update Grub configuration: update-grub
  16. Leave the chroot: exit; umount /mnt/* /mnt
  17. shutdown

Now you can detach the secondary virtual disk and create a new VM with it. If everything worked correctly, it will boot up.

Mac OS X 10.8 Mountain Lion Review

So I finally upgraded to Mountain Lion. I completely skipped over Lion because I didn’t like how Apple was iOS-ifying everything and had just stayed on Snow Leopard until a few days ago. Personally, I think Snow Leopard was the best operating system ever released. It was super stable and had everything you could ask of an operating system. I never really liked Leopard because it never worked 100% stable for me (though it did bring Time Machine and QuickLook, both of which are features I use every day). Tiger was great too back in the days, but if you look at it now, the GUI looks totally inconsistent.

Now that Apple is discontinuing security updates for Snow Leopard and an increasing number of apps requires Lion or newer, I had not much of a choice but upgrade.

This isn’t a full review of Mountain Lion. If you want to read one, check out John Siracusa’s epic review at Ars Technica. So far my impressions are:

Stability and speed: Mountain Lion is just as stable as Snow Leopard. It is also noticeably more responsive than Snow Leopard. I don’t think this has anything to do with actual speed, but more of a psychological thing: Safari now renders progressively, and many apps already let you interact with them while they’re still starting up (previously they would have been frozen for another second or two while they finished their startup prcedure).

iOS-ification: Launchpad is completely useless, but luckily Spotlight and the Dock still work exactly as they always have and will continue to be my preferred way of launching applications.

Auto Save however is outright obnoxious. You can no longer Command-D to hit the “Don’t Save” button when you want to close a window discarding changes. [UPDATE: Can’t believe it took me half a year to figure out that Command-Backspace can be used instead as an alternative to the old Command-D.] That window doesn’t even respect NSNavPanelExpandedStateForSaveMode (i.e. clicking the disclosure triangle is not persistent). “Save as” is now a secondary menu option behind “Duplicate”. iWork and TextEdit now show a file browser upon launch instead of opening a blank document. Save as defaults to iCloud instead of the local hard drive. And there are probably dozens of other things.

Here are some useful defaults commands to make it slightly less painful, but you still can’t completely disable Auto Save. Luckily I spend most of my time in apps that don’t use Auto Save (e.g. Microsoft Office, TextWrangler, TextMate, TeXShop).

defaults write -g NSNavPanelExpandedStateForSaveMode -bool TRUE # always expand open/save dialog
defaults write -g NSDocumentSaveNewDocumentsToCloud -bool FALSE # save locally instead of to iCloud by default

Also, check “Ask to keep changes when closing document” in the General pane in System Preferences.

Hold-to-umlaut is annoying on a full-size keyboard. Luckily you can re-enable key repeat:

defaults write -g ApplePressAndHoldEnabled -bool false # enable key-repeat

FileVault 2 is simple to enable, as secure as software-based full-disk encryption can be (according to several researchers) and has no noticeable performance hit. If you’re using it, you should enable deep sleep, otherwise the disk remains unlocked during sleep:

sudo pmset -a destroyfvkeyonstandby 1 hibernatemode 25

One thing that Apple could improve: after waking from deep sleep and entering your password at the EFI screen, that password should also be passed to the screensaver unlock screen (similar to how it’s passed to the loginwindow when booting). (this might be worth filing a bug report)

All of my favorite hidden Dock settings still work:

defaults write showhidden -bool YES # make hidden apps transparent
defaults write no-glass -boolean YES # disable 3D dock
killall Dock

The one thing that doesn’t really work anymore is dragging widgets out of Dashboard after enabling developer mode:

defaults write devmode -bool YES # enable dashboard dev mode
killall Dock

If you uncheck “Show Dashboard as a space” in the Mission Control pane in System Preferences, you can actually drag out the widget, but more often than not, it will just vanish along the way and won’t reappear until you kill the Dock.

Messages: I find it slightly annoying that Messages lists every single phone number and email address in the Show Info screen for every buddy, even if they don’t have iMessage activated. In fact, it even shows them after you disable iMessage in Messages’ preferences. Also, I miss the new message popup in the top right corner of my screen. Now, the only indication of a message received while you were away from your computer is a small number badge on the messages icon and a notification in Notification Center (which you don’t see until you open Notification Center). In fact, it doesn’t even show the message window until you click the icon (which may actually be a bug).

Notification Center is a very nice Growl replacement. I mainly need it for Mail and iChat, so I didn’t even bother installing something like Bark to forward Growl messages to Notification Center.

Full Screen is useless on a multi-screen setup, but running apps in full screen is pointless anyway on all but the smallest screens. Spaces used to be a pretty neat feature to switch between multiple sets of apps. Unfortunately, the old spaces (which you could access using Ctrl plus a number key or Ctrl plus the arrow keys) are gone and the new spaces can only be used to switch between multiple full-screen apps.

Most of my complaints are a matter of getting used to. When upgrading to a new OS, you always gain some things and you lose some things The only major issue I have is Auto Save. As long as my everyday apps don’t support it, I’ll be happy. Once they do (in Microsoft Office 2015 perhaps), I’ll need to find some way to get around it or get used to it.

Everything else is a reasonable tradeoff for being on the most recent OS version again.

I do remember how much my Windows friends complained six years ago when Vista changed everything they were used to after a decade of Windows 95 thru Windows XP. Or how some of my Linux friends complain about how Gnome 3 is so much worse than Gnome 2.

Installing Apple Remote Desktop 3.6.1 without first installing the boxed version

Apple Remote Desktop 3.0 was released in 2006. The current version is 3.6.1, and as such your six year old boxed copy license still entitles you to run it.

ARD has undergone some major changes during that time: most notably, Apple switched it from a Postgres database to an SQLite database, which greatly reduced its memory footprint and made it much more self-contained.

After reinstalling Mac OS X on my computer, I didn’t want to first install my boxed copy (version 3.2) because I didn’t want it to bloat my system with a copy of Postgresql that would get replaced by the update anyway.

After six years, it’s a safe bet that the downloadable Admin Update 3.6.1 does not require any previous version’s files. However, the installer checks for the existence of a previous version before allowing you to select the destination drive. This check can be satisfied by first running

defaults write /Applications/Remote\ CFBundleShortVersionString -float 3.0

I’d like to point out that it still requires the license key that came in the box when you first run ARD.