Acronis ExtremeZ-IP Seamless Integration of Macs into Windows Infrastructure

Reader finds Mavericks SMB problem related to Deduplication on Windows Server

Jim Myers discovered that the Deduplication feature of Windows Server 2012 causes Mavericks SMB file sharing problems, as well as problems with SMB changing permissions on the server, which other readers have also reported. As with other readers, forcing CIFS avoids the problems. Turning off Deduplication is not an option for Myers, and OS X 10.8 doesn't have the problem.

Myers reports:

I have one location that has a 2012 R2 server and having issue with only the 10.9 users copying some files to their Desktop. I have tracked it down to the fact that Deduplication is causing the issue. You can have the 10.9 user attach via CIFS and that will resolve the issue.

Come to find out the files that were causing the issue had been de-duped and in the Get Info window it would show the actual file size, but then it would also show zero bytes on disk, meaning the file was a duplicate on the server and it only contains metadata. Thru additional testing I have these facts: (The results were from 10.9.3/10.9.4 and from different computer with different levels of users).

  1. CIFS can copy the file without error.
  2. SMB, when you try to copy the file, you will get a dialog that you don't have permissions. If you look at the system log, you will see several "sandbox" errors.
  3. SMB, if you open and close the file, you can copy it then. After several minutes, you will be denied again.
  4. SMB, if you open the file and do a Save-As, you will be able to copy the file without error, no time limit.
  5. SMB, You can "Duplicate" the file and be able to copy the duplicate file. No time limit.
  6. SMB, You can copy the problem file with Terminal without issue.
  7. Tried a couple of the popular Finder replacements and under SMB, they all had the same issues. They worked with CIFS.
  8. On computer with 10.8.x, CIFS would cause issues of changing permissions on the server. SMB seems to be ok now with a 10.8 machine.

In summary, I have two options, turn off Deduplication (which is hard to justify) or run the 10.9 computers with CIFS and other systems with SMB.

Not sure who to point the finger at, but wanted to pass along this info to help anyone else have strange issues with 10.9.x and 2012 Win servers running Deduplication. Did not do any testing on any other version of Windows servers. We are starting to migrate from Netapp devices to 2012 servers and had hopes for a smooth transfer.

If you can confirm or rebut Myers' conclusions .

For more articles on these issues, see Mavericks File Sharing Tips and Reports.