Wubi is listed an a safe installation method

[Carey Underwood]

Wubi is offered as a "safe way of installing ubuntu", despite known issues that often cause the OS hosting the filesystem it is installed on to become unbootable if the Wubi install is not cleanly shutdown. This in unacceptable for several reasons:
 * There are known crashers in every release, which haven't been isolated sufficiently to allow a blacklist
 * Even with a blacklist, there are many reasons why a system may shutdown unexpectedly. User's are not urged to take precautions against unexpected power outages, for instance.
 * A user will often naively choose to use a Wubi installation when their system doesn't boot off a livecd. This makes recovery far more difficult, as now they have to troubleshoot a LiveCD or LiveUSB boot without the benefit of a working operating system to build it from.

Additionally, it is commonly accepted that a modern filesystem should be able to withstand a hard shutdown. Power-cycling is often given as a valid alternative to a lengthy procedure to recover or reset a partially debilitated system. Wubi breaks this assumption. Despite this, Wubi users are not cautioned against such approaches, nor are they instructed explicitly on the more rigorous approaches of shutting down in such a state (alt-sysrq-reisub for instance, or ssh'ing from another machine). Many of those techniques are considered advanced, and are in direct conflict with the target demographic of Wubi.

Wubi's own website severely downplays the risks involved: the only warning is midway through a 5000 word faq, and is worded such that an inexperienced user (their target market) could not reasonably be expected to divine the consequences of the action. Indeed, it states "try to avoid unplugging the power", as if it was merely a nuisance to be avoided.

Given this, I feel that Wubi should be relegated to an Unsupported installation method, removed from the LiveCD's Windows Autorun prompt, and specifically discouraged in the official documentation and communication channels (irc channels, mailing lists, wiki, etc).

[Agostino Russo (ago)]

I am not aware of issues with the host file-system due to Wubi use, if you do please feel free to open a bug report (and copy ntfs-3g).

What may happen is the opposite, the _guest_ filesystem may become unbootable after an abrupt shutdown, because a data loss for the host may result in a loss of journal for the guest. Because of that, the ntfs driver has been patched and it is mounted in a way (sync-io) which makes the writes to the host file system almost immediate. Since then I haven't seen any report of _guest_ file system corruption as a result of abrupt shutdown. Yet another issue is that if your windows filesystem is dirty (because for instance you didn't shut down cleanly from Windows) then (depending on the version of ntfs-3g) you might not be able to boot into ubuntu until you clean your filesystem, again this is not a case of Wubi damaging the host file system, the issue is that fsck for ntfs is not available in linux, although more recent incarnations of ntfs-3g should be able to cope with simpler cases.

Please note that abrupt shutdowns are unhealthy, and may end up damaging your file system, but this will happen whether you use Wubi or not, a simple web search can confirm that.

[Matthew East (mdke)]

Until and unless there is a change in the policy of the project to discourage Wubi (not currently the case), this isn't a website bug, so I'm closing that particular task.