Boot-repair is a product that has appeared in the past year or so and has speedily been incorporated in community-editable support documentation (basically all Ubuntu documentation). There's no question that the author has put a lot of effort has gone into creating and maintaining Boot-repair and it has apparently been embraced as a very useful tool by the community at large.
But I wouldn't recommend it for Wubi installations and here's why...
Wubi boot problems are different
There are some key differences in the way that Wubi boots. It uses the Windows boot mangler, not the bootloader in the drive MBR to boot. So that's the first thing to check... do you actually have boot problems or is it something different?
If Windows boots okay then boot-repair is not for you
As mentioned, Wubi boots via the Windows boot manager (yes that was a deliberate typo before). So technically your computer boots okay. Boot-repair is more concerned with the boot mechanisms that occur prior to the Windows boot manager showing e.g. the bootloader (drive MBR), the boot flag, etc. So running it isn't going to help. In one case it has stopped Windows booting. To be fair to the author, the problem mentioned in that thread has apparently been fixed, but I'm not sure that boot-repair is mature enough to handle all the myriad of Windows configurations out there.
If Windows doesn't boot, then you should use Windows Repair instead
As stated before, if you do have issues with Windows, then your best bet is a Windows repair disk. Windows repair is an official Windows repair mechanism supported by Microsoft, who hopefully understand their product.
If Wubi isn't booting then probably you need to run chkdsk
This cannot be done using boot-repair, only through Windows or Windows Repair. The most popular post on this blog is all about the damaged root.disk. This is by far the most common problem with Wubi installs, and the first thing you should consider when you have issues.
What Boot-repair will do
Boot-repair detects Wubi installs and will fsck the root.disk (fsck will fix any ext4 file system damage on the virtual disk). It's not always clear to new Ubuntu users how to do this, since you need to create an Ubuntu CD/USB, boot from it, mount the partition containing the root.disk and then fsck it. There are many guides on how to do all this, but of course it's easier to have this all automated for you.
Summary
I have no doubt that boot-repair has helped many people - and there don't seem to be too many misgivings about it out there in the community. But at the same time, in my opinion, it's been incorporated too rapidly into the official documentation e.g. here without sufficient warning that the tool is not officially supported by Canonical, and in some cases, might be classified as experimental.
Showing posts with label Problems. Show all posts
Showing posts with label Problems. Show all posts
Monday, August 20, 2012
Thursday, July 5, 2012
What's wrong with Wubi/Ubuntu
It speaks volumes that the most popular post on this blog is Missing the root.disk. It has nearly double the hits to the next most popular post (that also relates to Wubi boot problems).
What does this mean: to be missing the root.disk?
Well it's the catastrophic failure of Wubi, the damage and possible destruction of the virtual disk, in other words, the entire Ubuntu operating system and data. There really can't be much worse of a failure.
What is the cause?
It could be the forced shutdown of the computer, for example, due to a system freeze. In some cases, users reported a crash. In other cases, they reported nothing more than running available updates. It's not conclusive what the main cause is.
Why do people force shutdown?
There are probably many reasons this happens... like any bug that causes a system freeze. E.g. on my 12.04 Ubuntu install when I come back from suspend the screen sometimes remains black (mouse still visible). This isn't a freeze but there is no obvious way to shutdown or restart and no apparent fix/workaround. It would be totally understandable that some people might force shutdown if that happened to them. Especially coming from a Windows background where there is no alternative to REISUB. In fact, on my test Windows 8 install it freezes frequently and - as far as I know - that's my only option to reset.
So usability bugs like that could also be behind the corruption.
PS For this particular bug, I generally Ctrl+Alt+F1 and restart the lightdm desktop service (but it still kills all open apps).
Why does a forced shutdown corrupt the ext4 and/or ntfs file system?
This is perhaps the more relevant question. Maybe the journalling built into ext4 leads to corruption (speed over stability?). But this is pure speculation - and I thought Wubi installs were supposed to automatically sync all changes, precisely to avoid this problem.
And why would this affect the root.disk, a fixed-size file on NTFS...why does Wubi even update anything that could lead to this fixed file becoming corrupt? This seems like a major flaw.
How unstable is Wubi?
It's not possible to answer this without understanding how many people use Wubi and how many of those experience corruption of the root.disk. The fact is that I have never lost a root.disk to corruption in multiple years of testing Wubi, and over a year of continual use of Wubi (running the development releases)... so while I can't definitively say what is going on, I don't believe it's that unstable.
Regardless, the fact is, it shouldn't happen to anyone, and clearly it happens to many.
Why do people use Wubi?
I get that Wubi is a great way to try out Ubuntu without partitioning. It runs extremely close to a normal dual boot, that it showcases Ubuntu for those that are understandably nervous about partitioning. That makes sense. But why do they people keep on using it? Probably because it works too well. There isn't a whole lot of understanding about why it's not a great idea to do all your university coursework on a Wubi install and not bother to back it up. There also isn't any notification or warning when you install Wubi from here that there could be problems ahead or even an explanation of how Wubi is different unless you follow the links. In short, there's no reason for a user to switch to a partitioned install (usually until a major failure and the resulting investigation).
What do I think about Wubi?
I think it's pretty amazing to try out Ubuntu, but that it's poorly supported: I don't believe there is a credible maintenance and testing infrastructure for Wubi. If there were then you would see some effort to resolve these sorts of issues. And from experience I can assure you that getting even well-understood, major Wubi issues resolved (even when the fix is known), can be like pushing a rope.
Having said that, 12.04 is probably the most stable Wubi release ever - there's a huge drop in support requests. So it's working better than ever before and it seems to be popular and part of Canonical's strategy to spread Ubuntu.
Wubi maintenance
I touched on the fact that I don't believe there is a credible maintenance plan in place for Wubi. My impression is that, in general, Canonical's resources are stretched too thin. There are many important, unresolved issues with Ubuntu at any point in time, and Wubi's issues are obviously not high on that list. I've been using 12.04 since it's release and I've found a number of usability bugs that make it a frustrating experience. On top of that, the seemingly small Ubuntu developer team are always fully occupied, working hard to produce these relentless 6 month releases, which I believe is far too frequent. All that time spent on a development release for zero production users is time taken away from millions of real production users. This doesn't make any sense to me whatsoever. It should be the other way around. Because of this endless cycle of less than perfect releases and not fixing existing problems they are slowly going to whittle away at the support base and scare off newcomers. So... in short I believe the Wubi maintenance issues are minor compared to the general maintenance issues.
What does this mean: to be missing the root.disk?
Well it's the catastrophic failure of Wubi, the damage and possible destruction of the virtual disk, in other words, the entire Ubuntu operating system and data. There really can't be much worse of a failure.
What is the cause?
It could be the forced shutdown of the computer, for example, due to a system freeze. In some cases, users reported a crash. In other cases, they reported nothing more than running available updates. It's not conclusive what the main cause is.
Why do people force shutdown?
There are probably many reasons this happens... like any bug that causes a system freeze. E.g. on my 12.04 Ubuntu install when I come back from suspend the screen sometimes remains black (mouse still visible). This isn't a freeze but there is no obvious way to shutdown or restart and no apparent fix/workaround. It would be totally understandable that some people might force shutdown if that happened to them. Especially coming from a Windows background where there is no alternative to REISUB. In fact, on my test Windows 8 install it freezes frequently and - as far as I know - that's my only option to reset.
So usability bugs like that could also be behind the corruption.
PS For this particular bug, I generally Ctrl+Alt+F1 and restart the lightdm desktop service (but it still kills all open apps).
Why does a forced shutdown corrupt the ext4 and/or ntfs file system?
This is perhaps the more relevant question. Maybe the journalling built into ext4 leads to corruption (speed over stability?). But this is pure speculation - and I thought Wubi installs were supposed to automatically sync all changes, precisely to avoid this problem.
And why would this affect the root.disk, a fixed-size file on NTFS...why does Wubi even update anything that could lead to this fixed file becoming corrupt? This seems like a major flaw.
How unstable is Wubi?
It's not possible to answer this without understanding how many people use Wubi and how many of those experience corruption of the root.disk. The fact is that I have never lost a root.disk to corruption in multiple years of testing Wubi, and over a year of continual use of Wubi (running the development releases)... so while I can't definitively say what is going on, I don't believe it's that unstable.
Regardless, the fact is, it shouldn't happen to anyone, and clearly it happens to many.
Why do people use Wubi?
I get that Wubi is a great way to try out Ubuntu without partitioning. It runs extremely close to a normal dual boot, that it showcases Ubuntu for those that are understandably nervous about partitioning. That makes sense. But why do they people keep on using it? Probably because it works too well. There isn't a whole lot of understanding about why it's not a great idea to do all your university coursework on a Wubi install and not bother to back it up. There also isn't any notification or warning when you install Wubi from here that there could be problems ahead or even an explanation of how Wubi is different unless you follow the links. In short, there's no reason for a user to switch to a partitioned install (usually until a major failure and the resulting investigation).
What do I think about Wubi?
I think it's pretty amazing to try out Ubuntu, but that it's poorly supported: I don't believe there is a credible maintenance and testing infrastructure for Wubi. If there were then you would see some effort to resolve these sorts of issues. And from experience I can assure you that getting even well-understood, major Wubi issues resolved (even when the fix is known), can be like pushing a rope.
Having said that, 12.04 is probably the most stable Wubi release ever - there's a huge drop in support requests. So it's working better than ever before and it seems to be popular and part of Canonical's strategy to spread Ubuntu.
Wubi maintenance
I touched on the fact that I don't believe there is a credible maintenance plan in place for Wubi. My impression is that, in general, Canonical's resources are stretched too thin. There are many important, unresolved issues with Ubuntu at any point in time, and Wubi's issues are obviously not high on that list. I've been using 12.04 since it's release and I've found a number of usability bugs that make it a frustrating experience. On top of that, the seemingly small Ubuntu developer team are always fully occupied, working hard to produce these relentless 6 month releases, which I believe is far too frequent. All that time spent on a development release for zero production users is time taken away from millions of real production users. This doesn't make any sense to me whatsoever. It should be the other way around. Because of this endless cycle of less than perfect releases and not fixing existing problems they are slowly going to whittle away at the support base and scare off newcomers. So... in short I believe the Wubi maintenance issues are minor compared to the general maintenance issues.
Tuesday, August 2, 2011
Missing the root.disk
I wrote earlier about the Mystery of the disappearing root.disk. I've seen a number of additional cases since that post - and not all have been catastrophic, so thought I'd discuss what the steps are to attempt recovery.
My belief is that this problem is largely the result of manually shutting down your computer when the Wubi install is hanging. But there have been cases where corruption has occurred without manual poweroffs and I've noticed that some files I delete from within Wubi are 'recovered' later by Windows.
But it is important for users to resist the urge to 'hit the restart/power button' when the Wubi install is hanging. For any OS this is a bad idea and can lead to problems. For Wubi installs it can be fatal. Instead refer to the Wubi Guide for other options.
The first thing you'll notice may be Windows running an automatic CHKDSK or when you try to boot Ubuntu you end up at a GRUB> prompt.
Then when you boot Windows and look in the C:\ubuntu\disks directory you'll notice the root.disk is missing. In some cases, the \ubuntu\disks directory is missing completely or is corrupted.
Running chkdsk
Depending on the problem, Windows may have run an automatic chkdsk or you may need to run it manually. It's not always necessary, but it will never hurt, so the first thing is to run it.
Go to My Computer on XP or Computer on Vista/7, right click the drive you installed Ubuntu on e.g. right click on C:, select Properties, select the Tools tab, then under Error-checking click Check now. Select to Automatically fix file system errors or Scan for and attempt recovery of bad sectors (I usually don't use this, but if you hard drive has problems it's a good idea). When the drive you installed on is C: the computer will tell you it has to schedule the scan for the next time you start your computer. Reboot to complete.
Locate recovered files/directories
The first thing to do is to look for the \found.000 folder on the drive in question i.e. C:\found.0000. This is hidden by default and (on my Windows 7 install) I also had to tell Windows not to "Hide protected OS files" just to see it. You may also have to recover from an administrator command prompt on Win7 (see below).
So now you look for your root.disk (or other .disk files) and copy them back to the \ubuntu\disks folder. If the entire \ubuntu\disks folder is missing, you'll likely find a dir0000.chk directory and within that the root.disk, swap.disk and empty \boot\grub folders. Copy this back to \ubuntu renaming the directory to disks.
If you're missing the root.disk but there is no file of that name, it may have been renamed chk0000.chk. Rename this to root.disk and copy back to \ubuntu\disks.
If the corruption was minor, then likely everything will work fine. If the corruption is major Windows may not even recover the root.disk at all.
Win7/Vista command line instructions
Hit the START key, enter CMD, then look above and right click on CMD.exe and select "Run as Administrator", as shown below. From Windows 8, type "CMD" on the Metro page, right click, and then look on the bottom for "Run as administrator.
Check for the hidden recovery directories: dir /a:h
Check each \found.??? directory:
Or if the whole \ubuntu\disks folder is missing:
My belief is that this problem is largely the result of manually shutting down your computer when the Wubi install is hanging. But there have been cases where corruption has occurred without manual poweroffs and I've noticed that some files I delete from within Wubi are 'recovered' later by Windows.
But it is important for users to resist the urge to 'hit the restart/power button' when the Wubi install is hanging. For any OS this is a bad idea and can lead to problems. For Wubi installs it can be fatal. Instead refer to the Wubi Guide for other options.
The first thing you'll notice may be Windows running an automatic CHKDSK or when you try to boot Ubuntu you end up at a GRUB> prompt.
Then when you boot Windows and look in the C:\ubuntu\disks directory you'll notice the root.disk is missing. In some cases, the \ubuntu\disks directory is missing completely or is corrupted.
Running chkdsk
Depending on the problem, Windows may have run an automatic chkdsk or you may need to run it manually. It's not always necessary, but it will never hurt, so the first thing is to run it.
Go to My Computer on XP or Computer on Vista/7, right click the drive you installed Ubuntu on e.g. right click on C:, select Properties, select the Tools tab, then under Error-checking click Check now. Select to Automatically fix file system errors or Scan for and attempt recovery of bad sectors (I usually don't use this, but if you hard drive has problems it's a good idea). When the drive you installed on is C: the computer will tell you it has to schedule the scan for the next time you start your computer. Reboot to complete.
Locate recovered files/directories
The first thing to do is to look for the \found.000 folder on the drive in question i.e. C:\found.0000. This is hidden by default and (on my Windows 7 install) I also had to tell Windows not to "Hide protected OS files" just to see it. You may also have to recover from an administrator command prompt on Win7 (see below).
So now you look for your root.disk (or other .disk files) and copy them back to the \ubuntu\disks folder. If the entire \ubuntu\disks folder is missing, you'll likely find a dir0000.chk directory and within that the root.disk, swap.disk and empty \boot\grub folders. Copy this back to \ubuntu renaming the directory to disks.
If you're missing the root.disk but there is no file of that name, it may have been renamed chk0000.chk. Rename this to root.disk and copy back to \ubuntu\disks.
If the corruption was minor, then likely everything will work fine. If the corruption is major Windows may not even recover the root.disk at all.
Win7/Vista command line instructions
Hit the START key, enter CMD, then look above and right click on CMD.exe and select "Run as Administrator", as shown below. From Windows 8, type "CMD" on the Metro page, right click, and then look on the bottom for "Run as administrator.
Check for the hidden recovery directories: dir /a:h
Check each \found.??? directory:
C:\>cd \found.000
C:\found.000>dir
Volume in drive C is OS
Volume Serial Number is B4B7-99A8
Directory of C:\found.000
19/07/2011 02:02 PM 15,000,000,000 file0000.chk
1 File(s) 15,000,000,000 bytes
0 Dir(s) 222,258,069,504 bytes free
C:\found.000>move file0000.chk \ubuntu\disks\root.disk
1 file(s) moved.Or if the whole \ubuntu\disks folder is missing:
C:\>cd \found.000
C:\found.000>dir
Volume in drive C is OS
Volume Serial Number is B4B7-99A8
Directory of C:\found.000
19/10/2012 04:51 PM <DIR> .
19/10/2012 04:51 PM <DIR> ..
19/07/2011 02:02 PM <DIR> dir0000.chk
0 File(s) 0 bytes
3 Dir(s) 222,258,069,504 bytes free
C:\found.000>dir dir0000.chk
Volume in drive C is OS
Volume Serial Number is B4B7-99A8
Directory of C:\found.000\dir0000.chk
19/10/2012 04:51 PM <DIR> .
19/10/2012 04:51 PM <DIR> ..
24/02/2012 12:22 AM <DIR> boot
06/11/2012 09:28 AM 13,000,000,000 root.disk
15/11/2011 09:28 PM 268,435,456 swap.disk
2 File(s) 13,268,435,456 bytes
3 Dir(s) 127,904,968,704 bytes free
C:\>move dir0000.chk \ubuntu\disks
1 dir(s) moved.
I hope this helps you to recover your files. Remember to backup important data on your Wubi install. There's no reason to install important personal files on a root.disk - you can access them easily on the /host partition.
Updated 2012-11-06: added some more screenshots, enhanced DOS commands
Updated 2012-11-06: added some more screenshots, enhanced DOS commands
Thursday, December 16, 2010
Canonical has a strange sense of priorities
So it's nearly a month since the latest Grub update in the current Long Term Release, Lucid Lynx 10.04, put the boots to Wubi installs. In addition to the usual alarming, but generally harmless, grub rescue> prompt problem, which has been around since Lucid was first released in April, the newer failure to boot issue has been totally ignored by Canonical.
This boot failure problem started cropping up in July with grub errors about 'loadfont', but didn't seem to affect everyone. With the November 20 release it now appears to be much more widespread - a fresh install of 10.04.1 with the updates applied does not boot. (*Ubuntu must be installed to the same partition as Windows for this problem to occur).
The reason that it only affects Wubi installs on the same partition as Windows is that it is the grub-install command that is corrupting the /boot/grub directory, and when you update package grub-pc it runs grub-install to try to update the wubildr (Wubi bootloader) - believed by the grub devs to be a required action; BUT, Wubi installs on a different partition slip through the net as the buggy code fails to identify them as Wubi installs. This means that grub-install aborts and the wubildr is not updated - but ironically these still boot.
So the whole idea of updating wubildr and breaking Wubi installs in the process is pointless - why don't they just bypass the update altogether.
So... why haven't the devs rushed to fix this? Even the Ubuntu Release Manager Steve Langasek was notified of the 'critical' issue... but no response at all. The devs appear to be hard at work preparing for the next Ubuntu release (11.04 Natty Narwhal) - in the meantime, unsuspecting users who decide to try out Ubuntu are left to discover what a grub rescue prompt is, or why their new OS fails to boot.
So, in summary, Canonical doesn't seem to give a hoot about the current users who are breaking their computers trying out the 'user friendly' Wubi option. Are they just blindly churning out (buggy) release after (buggy) release as though this is a strategy for long-term success? Hard to say, but let's just say - I'm confused. If they don't want to support Wubi, why don't they just pull it from their main download site to protect the computers of unsuspecting users?
And thanks to everyone on Ubuntuforums.org who are working hard to help the affected users. It's great to have such strong community support, but if Canonical is relying on this for current release support it's pretty pathetic.
This boot failure problem started cropping up in July with grub errors about 'loadfont', but didn't seem to affect everyone. With the November 20 release it now appears to be much more widespread - a fresh install of 10.04.1 with the updates applied does not boot. (*Ubuntu must be installed to the same partition as Windows for this problem to occur).
The reason that it only affects Wubi installs on the same partition as Windows is that it is the grub-install command that is corrupting the /boot/grub directory, and when you update package grub-pc it runs grub-install to try to update the wubildr (Wubi bootloader) - believed by the grub devs to be a required action; BUT, Wubi installs on a different partition slip through the net as the buggy code fails to identify them as Wubi installs. This means that grub-install aborts and the wubildr is not updated - but ironically these still boot.
So the whole idea of updating wubildr and breaking Wubi installs in the process is pointless - why don't they just bypass the update altogether.
So... why haven't the devs rushed to fix this? Even the Ubuntu Release Manager Steve Langasek was notified of the 'critical' issue... but no response at all. The devs appear to be hard at work preparing for the next Ubuntu release (11.04 Natty Narwhal) - in the meantime, unsuspecting users who decide to try out Ubuntu are left to discover what a grub rescue prompt is, or why their new OS fails to boot.
So, in summary, Canonical doesn't seem to give a hoot about the current users who are breaking their computers trying out the 'user friendly' Wubi option. Are they just blindly churning out (buggy) release after (buggy) release as though this is a strategy for long-term success? Hard to say, but let's just say - I'm confused. If they don't want to support Wubi, why don't they just pull it from their main download site to protect the computers of unsuspecting users?
And thanks to everyone on Ubuntuforums.org who are working hard to help the affected users. It's great to have such strong community support, but if Canonical is relying on this for current release support it's pretty pathetic.
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