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There seems to be an issue with using SVN on a NTFS deduped volume.

To save space on my SSD for some huge development checkouts (> 5 GB each) i enabled data deduplication on the volume. This seems to cause SVN all kinds of grief and madness.

The usual symptom is an E270001: Symlinks are not supported on this platform error which basically dooms the checkout. You cannot commit, merge or do anything on it anymore. Basically svn + deduped NTFS seems utterly broken.

There was some mail thread from 2012 at (Subversion Mailing List) which talked about a similar problem, just this time with special file status.

I assume the Symlinks not supported issue is basically the same.

Is there any way to get SVN work properly with deduplicated NTFS volumes (other than hacking up the appropriate support for APR myself APR Issue 47630?).

schlenk
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I've found svn works without complaint under NTFS Compression. My repositories were somewhere around 15% smaller on-disk after enabling compression. while it doesn't provide as much potential storage savings as deduplication, it does have the advantage of working reliably and with significantly less time expense than hacking around the dedup incompatibility.

Chris Terry
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If SVN doesn't support symlinks, it won't support Server 2012 Data Deduplication, since that's how the feature works - "optimized" files are replaced by "reparse points," which are junction points to the data chunks that are needed to reconstitute the file.

Symlinks are an inherent and integral part of Server 2012 Data Deduplication, and there no getting around that. Not what you want to hear, I'm sure, but that's the long and the short of it. Symlink support is a necessary prerequisite to supporting Server 2012 Data Deduplication.

HopelessN00b
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    Well, technically SVN supports symlinks in a hackish way, but it seems to confuse reparse points with unix style symlinks. Hmm, maybe i should simply monkey patch the FindFirstFile API for svn so it doesn't notice the reparse points... – schlenk Feb 12 '15 at 23:02
  • *Working copy must always go on Windows volume that is NOT deduplicated.* This workaround will be necessary until SVN receives a fix to treat dedup reparse points as regular files. Currently SVN mistakes the dedup reparse points for symlink and breaks things badly. – Mister_Tom Jan 04 '17 at 22:32