Frequent Drobo corruption after upgrading to OS X 10.8
On the same day I upgraded to OS X 10.8, I started seeing frequent volume corruption on my Drobo. The corruption persists even after I have reset and reformatted the Drobo, and can happen at any time - after copying a bunch of files, or even after starting up the Drobo. For example, I can use diskutil to verify that the Drobo is fine before shutting it down, only to find the volume corrupted when I power it on. Several times I even saw corruption after leaving the Drobo idle for several hours.
Here are some of the errors I see with diskutil when there is corruption.
Started file system verification on disk5s2 Drobo
Checking file system
Checking Journaled HFS Plus volume
Checking extents overflow file
Checking catalog file
Checking multi-linked files
Checking catalog hierarchy
Checking extended attributes file
Checking volume bitmap
Checking volume information
Volume header needs minor repair
The volume Drobo was found corrupt and needs to be repaired
Error: -69845: File system verify or repair failed
Underlying error: 8: POSIX reports: Exec format error
Started file system verification on disk5s2 Drobo
Checking file system
Checking Journaled HFS Plus volume
Checking extents overflow file
Checking catalog file
Invalid sibling link
The volume Drobo was found corrupt and needs to be repaired
Error: -69845: File system verify or repair failed
Underlying error: 8: POSIX reports: Exec format error
Started file system verification on disk4s2 Drobo
Checking file system
Checking Journaled HFS Plus volume
Checking extents overflow file
Checking catalog file
Checking multi-linked files
Checking catalog hierarchy
Checking extended attributes file
Overlapped extent allocation (id = 275951, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2081.NEF)
Overlapped extent allocation (id = 275952, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2082.NEF)
Overlapped extent allocation (id = 275953, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2083.NEF)
Overlapped extent allocation (id = 275954, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2084.NEF)
Overlapped extent allocation (id = 275955, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2085.NEF)
Overlapped extent allocation (id = 275956, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2086.NEF)
Overlapped extent allocation (id = 275957, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2087.NEF)
Overlapped extent allocation (id = 275958, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2088.NEF)
Overlapped extent allocation (id = 275959, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2089.NEF)
Overlapped extent allocation (id = 275960, /Aperture Backups/Aperture Library 2008.aplibrary/Masters/2008/09/07/20080907-231132/DSC_2090.NEF)
Overlapped extent allocation (id = 600188, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/03/20100803-090117/DSCF9143.RAF)
Overlapped extent allocation (id = 600191, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145503/DSC_6409.NEF)
Overlapped extent allocation (id = 600192, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145503/DSC_6410.NEF)
Overlapped extent allocation (id = 600193, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145503/DSC_6411.NEF)
Overlapped extent allocation (id = 600194, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145503/DSC_6412.NEF)
Overlapped extent allocation (id = 600196, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145617/DSCF9178.RAF)
Overlapped extent allocation (id = 600197, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145617/DSCF9179.RAF)
Overlapped extent allocation (id = 600198, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2010/08/04/20100804-145617/DSCF9180.RAF)
Overlapped extent allocation (id = 601790, /Aperture Backups/Miscellaneous Library.aplibrary/Masters/2011/09/29/20110929-225140/IMG_0565.MOV)
Checking volume bitmap
Volume bitmap needs minor repair for under-allocation
Checking volume information
The volume Drobo was found corrupt and needs to be repaired
Error: -69845: File system verify or repair failed
Underlying error: 8: POSIX reports: Exec format error
Most times DiskWarrior can usually fix the problems in place, but there were times when the corruption was so severe DiskWarrior would instruct copying to a new disk.
I have been working with Drobo Support for the past 3 months and they have replaced the Drobo 3 times to no avail. I see this problem on 3 different Macs and on different interfaces (FW800, USB 3.0 and USB 2.0) and even with base OS installs of 10.7 and 10.8. At this point I have ruled out cables, drives and software conflicts. Drobo Support even had me try different versions of firmware. We are now out of ideas and I'm open to suggestions on tracking down the root cause.
Alvin