Tuesday, May 3, 2011

Installing Wubi - common problems

Since the release of Natty Narwhal 11.04 a few days ago, I've been monitoring various support forums looking for issues. The good news is that I'm not seeing anything new and exciting, just the standard problems users have with installs. So that's good, but I realised that now is probably a good time to catalogue some of these common problems - and their solutions (if they exist).

Wubi installs involve two distinct processes. First the Windows install where you select the user name and password, the target drive, and the size of the install. Wubi then finds a local desktop CD image or downloads one, creates virtual disks, modifies the Windows boot manager, sets up a special file with installation instructions and tells you to reboot.
The second part is when you reboot and select Ubuntu from the Windows boot manager. This boots a linux kernel (through grub4dos and grub2), and then runs the standard Ubuntu installer (Ubiquity), which uses the special installation instructions created in Windows - so that no user interaction is required  (usually).

Important info
If you want an Ubuntu CD/USB: go to http://www.ubuntu.com/download/ubuntu/download (step 2, click on medium, and then SHOW ME HOW)
You can run wubi from the CD or standalone. If you run it standalone you can download the desktop CD ISO yourself and place it in the same folder as wubi.exe and it will use it (must be the same release).
You cannot install from an alternate ISO or a DVD ISO (burning a CD ISO to DVD is okay). Installing from a USB will fail if the USB partition is > 890MB (and it will copy the entire partition to your hard drive before failing - and that could be an 8GB file, so be careful).

When Wubi fails in Windows you should check the log file or post it on a support forum for help. To find the wubi log file, go to the %temp% folder (enter %temp% in your Windows explorer address bar) and open the file wubi-nn.nn-revnnn.log (n's represent release and wubi.exe revision)

Windows issues
  • Failure to download the metalink. Either you don't have internet access or you are installing 11.04 and you select Ubuntu-netbook. I mentioned the 11.04 Netbook problem in my last post, so nothing further to add there. 
  • You select to install to a drive that is actually a Dynamic disk. These are Windows specific and it won't let you 'boot from them' - and Ubuntu cannot see or boot from them either (unless they also happen to reside in the MBR partition table - in which case you run the risk of destroying data on dynamic drives that do not).  Solution: DO NOT INSTALL on dynamic drives. Either get rid of them or find an external drive.
  • You get a firewall notification asking whether to allow "pyrun.exe". This is the python executable that is actually running Wubi - and it is uses a bittorrent downloader to retrieve the desktop CD image. You need to give it access or the install will fail. Alternatively download the desktop CD ISO and place it in the same folder as wubi.exe (and ALSO remove the bad CD or wubi.exe will find it and fail again).
  • The CD was not created correctly (a bad burn). If you look in the wubi log it will tell you the md5sum failed or some other error (Errno13, 22). Solution: create a new CD or run wubi.exe standalone.
  • It's downloading the wrong version 64bit. It's not actually the wrong version. Wubi defaults to 64bit when the computer is capable (and some users do not know that their computers are 64bit). If you want 32bit then download the 32bit version and a) place it in the same folder as wubi.exe, b) burn it to CD or c) specify the command line option --32bit when running wubi.exe
  • IOError: [Errno 22] or [Errno 13]. This error can be associated with a bad burn, bad image, or even an optical drive incompatibility. Most likely a bad burn. You can either boot from the CD and get it to check itself, or remove the CD, and run wubi standalone (with or without the downloaded desktop CD ISO in the same folder). If you are not running from a CD, Errno13 can be associated with a permissions error (run as an administrator) or a corrupted file (run chkdsk).
  • Pyrun.exe says "No disk". This looks like a tight loop but it's not. Usually it's caused by a disk 'drive' assigned to an empty drive like a multimedia card reader. Either remove the cardreader or other peripheral or click cancel many times to get through it. To kill the install process open up task manager and kill pyrun.exe.

Please note - if you have an Ubuntu CD (matching the release and flavour of wubi.exe) in a disk drive, Wubi.exe (even if run standalone) will find it and use it. If the CD has a bad checksum or bad burn, it will cause the installation to fail - Wubi.exe might go through the motions of downloading a new CD, but often the first error will be fatal. 

When you reboot from Windows to complete the installation, and select Ubuntu the errors you encounter are related to the Windows boot manager, grub4dos, linux/hardware compatibilites, and the Ubuntu installer (Ubiquity).

Ubuntu/Ubiquity issues
  • If you find it boots straight back into Windows, then either Wubi failed to add an entry to the Windows Boot Manager, or the Windows boot manager Timeout is set to 0. In both cases, let it boot, right click on (My) Computer, Properties, Advanced, Startup & Recovery settings... and check the Timeout - make it 15 or more. Check the drop down box to see if the Ubuntu entry is there. NEVER set Ubuntu as default and the Timeout to 0 or 1 or Windows won't boot.
  • "Try hd(0,0): xxxx: No wubildr". This is not an error. Ignore it unless it accompanies "grldr not found". See one of my previous posts on this.
  • Reboots back to the Windows boot loader or grub> prompt. See the Wubi megathread, problem #2 (This won't happen on an initial install)
  • Grub rescue> prompt. See the Wubi megathread, Problem #1. (This won't happen on an initial install).
  • If you never get to see the installer, then you are having a problem booting the linux kernel. There could be a number of reasons... graphics card, other device incompatibilities. The best thing to do is search the support forums (e.g. ubuntuforums.org) for your particular computer brand/model and the specific release - often someone else has figured out what you'll need and published it. See here for how to supply boot workarounds.
  • You installer starts, but you get the message "no root file system is defined"This is often caused by Ubiquity failing to read the target partition. This message can also occur on a normal install,for a different reason (user error) but with Wubi there is no user interaction to select the target root partition. Some common causes are: you have some leftover GPT partition table data when you're using an MBR partition table; you have some fakeraid metadata but are not using raid, or you're using an unsupported Raid. In all cases, it's best to run the bootinfoscript and create a request for help on the forums to find a solution.
  • Other problems. If the installer halts for any reason, you have to collect logs otherwise no one will be able to do anything about it. Drop to terminal (CTRL+ALT+F2) and collect the logs (to \ubuntu\installation\logs.zip): 
sudo sh /host/ubuntu/install/custom-installation/hooks/failure-command.sh


    1. I'm having a problem where Wubi installer acts like everything is fine, but when I reboot, Ubuntu doesn't show up in the Windows Boot Manager. I *only* see Windows 7.... I found your post as you mention the problem, but you don't offer any solution and I'm pretty desperate...

      Where you mention this problem in your post, you simply say to check the timeout and to see if Ubuntu is there... Well.. it's NOT there, and that's the problem. I've tried a dozen times and it just won't add the entry... Any fix?

    2. aelfwyne, that's because it's not really straightforward and possibly risky (also not very common). Anyway - if you have vista/7 refer to this. Normally it happens on XP, in which case you have to edit your boot.ini (back it up first) and add the line: C:\wubildr.mbr="Ubuntu"

    3. After a couple of hours head-banging, reading the small-print and Googling I came here and found the advice "DO NOT INSTALL on Dynamic drives" - which is presumably the reason my Ubuntu via Wubi installation failed, all my disks being dynamic.

      Pity none of the official sites trumpeting the ease of running Ubuntu with Windows via Wubi sees fit to mention this little wrinkle.

      No, I'm not going to 'get rid' of my dynamic disks just for this purpose - they're too useful. And external drives are so slow there's little point to them except as back-up locations.

      So I'll pass on Linux and Ubuntu once again.

      Oh, and Wubi is a real pain. God only knows why it insists on a crawling Torrent download when the local Ubuntu depository is quick - or even why it goes straight to a unavoidable download when I have a perfectly good Ubuntu iso on my desk.

    4. Anonymous,
      Dynamic drives seem to have taken off with Windows 7 (i.e. recently). I'm sure the linux world will catch up soon and at least provide a user-friendly warning. But maybe the onus should be on Windows to warn that a) once you go dynamic you can't go back and b) they are not compatible with other operating systems.

      PS a torrent is generally faster than having everyone hitting the server directly (at least you should try it after a new Ubuntu release and then compare).
      PPS Wubi will use an ISO you downloaded - refer to the Wubi Guide on how this works.
      PPPS I've never noticed a huge lag running Ubuntu on an external drive. (I often use this for testing).

    5. i am getting this error after installing
      kernel panic - not syncing : VFS : Unable to mount root fs on unknown - block (0,0)

      any idea what it is, and how can i fix.

      i have windows xp sp3

    6. I suspect that the 'kernel panic - not synching' message is the same as the 'no root file system is defined' error - but with the new preinstalled 11.10 image installs (no ubiquity) it manifests as a failure to mount. See this bug report

    7. I've tried to install ubuntu 11.04 on my win 7 on a separate partition. I've chosen 24 GB version ( partition is 25 GB large). After this process i done, wubi closes and nothing is happening. On partiton there were created some files ( ~ 8oo mb) . What should I do?

    8. For wubi problems, please visit answers.launchpad.net/wubi or ubuntuforums.org or askubuntu.com. This blog isn't an ideal place for troubleshooting install issues. Any comments on known installation issues are welcome though.

    9. This comment has been removed by a blog administrator.

    10. Please note my previous comment about this blog not being a support site. In addition, comments that contain wubi log files will be deleted. Since I monitor http://answers.launchpad.net/wubi there is no need to post here. Thanks.

    11. What good is wubi for the average user when it is clearly full of failure? Yes, I get the error regarding "no root file system is defined". This sort of thing will only run people right back into the arms of Windows. Certainly, I have no choice but to do so as I am not a computer guru.

    12. Jay, actually Wubi is great for the average user because it enables them to try out Ubuntu without having to worry about partitioning. That problem you are getting is not related to Wubi - you'd get it with a normal Ubuntu install as well. All these problems I've listed on this page are unfortunate, but IMO they affect a minority of people who try Wubi. Even if you do have problems, you don't have to be a guru to solve them - there are many people willing to help - see the site links listed above.

    13. Hi. I installed an older version of Ubuntu before with the Wubi installer. I then did an upgrade of the Ubuntu to the latest 11.10 version but this did not work well. Icons were missing in Ubuntu and it was pretty messed up (with no option to shut down Ubuntu etc.). I therefore completely uninstalled ubuntu from within Windows 7 64 bit and downloaded the new Ubuntu 11.10 Wubi.exe. When I now execute the Wubi.exe I get the normal Win7 "User Account Control" notification asking if I want to allow the program to make changes to my computer. I answer with "yes" and now the installer should start. But it doesn't! I just get a quick change of the mouse pointer showing that something happened but then nothing. As if I never tried to execute the wubi.exe. No error messages no nothing. I abviously tried this in all compatibility flavours and as administrator. Always the same thing. Can anyone help me?

    14. Hi guys, sorry for posting the above on the wrong forum. I re-posted and got the problem resolved here http://askubuntu.com/questions/89027/why-does-wubi-exe-for-ubuntu-11-10-not-run-on-windows-7-64bit

    15. Hey - Tried to install it alongside windows, got to the end of the installation (after an hour) and only then did it decide to tell me "I don't have permission" or something. I'm running windows xp and I am using the only account on the system.

      1. That could be bug 862003 (which means the install is successful). Review your log file if unsure. That bug was introduced in release 11.10 - after I wrote this post - and it will be fixed with release 12.04 due out in a few weeks.

    16. I installed wubi on my vista machine so I could load ubuntu on an external usb drive, and rebooted. I got the screen showing to boot to either vista or ubuntu. When I select ubuntu I get an error
      File \ubuntu\winboot\wubildr.mbr
      I tried it twice with the same result. How can I fix this?

      1. In order to boot an OS from the USB the BIOS has to be able to 'see it' (via BIOS functions). Just because Windows can see it, doesn't mean that the BIOS is able to. That seems the most likely reason.

    17. After downloading wubi and following the steps, when I restart my computer I can choose Ubuntu but I get this message...

      windows boot manager
      windows failed to start
      1)insert windows install disc and restart
      2) choose your language settings and then restart
      3) click repair your computer
      if you do not have this disk talk to the system administrator
      file: \ubuntu\winboot\wubildr.mbr
      Status: 0X0000098
      Info: the selected entry could not be loaded because the application is missing or currupt.

      Any ideas?


      1. Wubi doesn't support computers with full UEFI boot on GPT disks. That seems the most likely problem if it's a new computer. If this applies to you, please check out the bug report for it here (nothing seems to be happening on it yet). Using the traditional dual boot with UEFI is supported.