@Ben Golding
I am not against a configuration option.
Of course, it seems better if it "just works" without configuration (in all environments), but otherwise configuration is supposed to be better than a "bug".

Most important is that you may need to submit a github pull request with working code in order to make it accepted by the plugin maintainer.

Why we should calculate symlinks at all?
Adding hudson.Util.isSymLink(File) wouldn't cause performance degradation because of page objects cashes in kernel.

Code changed in jenkins
User: Kanstantsin Shautsou
Path:
src/main/java/hudson/plugins/disk_usage/DiskUsageThread.java
http://jenkins-ci.org/commit/disk-usage-plugin/361984ea3af33b8cbbb6910e2e8ad8e8bac431a3
Log:
JENKINS-13247 don't calculate symlinks

Tested with one file and symlink to it in workspace.

Code changed in jenkins
User: Vojtěch Juránek
Path:
.gitignore
src/main/java/hudson/plugins/disk_usage/DiskUsageThread.java
http://jenkins-ci.org/commit/disk-usage-plugin/e1334059b37d17c0885fb940ce20fc41a1515163
Log:
Merge pull request #12 from KostyaSha/master

JENKINS-13247 don't calculate symlink file size

Compare: https://github.com/jenkinsci/disk-usage-plugin/compare/301ef38d342e...e1334059b37d

Hi,
I merged PR #12. Before I release it, what the concerns about performance actually are about? On JDK7, there's native support for checking if the file is symlink, on older JDKs rest of the hudson.Util.isSymlink() will be used, but it doesn't seem me that is would cause any significant issues. If I miss something, please let me know and I'll make skipping symlinks optional.
Thanks

Hi vjuranek,
Concerns about performance were the difference between before and after using isSymLink when there are a large number of files, for Windows vs Linux and for JDK6 vs JDK7 (and on Windows on JDK6, isSymLink uses jna).

I do not say that there is a problem, I have suggested to test in order to know.
Anyway, you know much more about this than me, so if you think that this should not be a problem, then it's ok and fixed now.
Thanks to care.

Actually I don't know much about windows and moreover haven't any win machine with large FS where I could test it. So if there is any volunteer how is willing to build the plugin from from trunk and test it, that would be great.

Everybody who wants performance i can advice update to java7.

Seems that fix resolves JENKINS-15974 as well. When are you going to kick-off new release?

seems to be fixed and released now => resolving issue