Last week, one of our customers experienced a system wide outage due to a new MAC on the network. That’s right… it is typed correctly. During the setup of a MAC OS Lion 10.7 installation, one of the users had a home folder set in their Active Directory properties. When the MAC user logged in and the laptop attempted to map the user’s home folder, the EMC Celerra NS40 NAS that serves as the back-bone of the network serving CIFS shares and about a dozen iSCSI LUNs to Microsoft Exchange, SQL Server, and VMware hosts, experienced a kernel panic and crashed….very ungracefully I might add. The outage only lasted about 2-3 minutes while the datamover failed over to the standby. However, it took nearly two hours to clean up the carnage post-failure. Not to mention, two hours outside of business hours to fail the unit back to the primary datamover.

Specifics about the exact cause are not 100% clear, but two things are known. First of all, MAC OS 10.7 uses a different SAMBA client than previous versions. Formerly, MAC OS used a bundled open source SAMBA software for Windows file share and network directory services. With 10.7, they have rolled their own and replaced the open source code with their own flavor of SAMBA. According to EMC, the root cause of the issue is that MAC OS 10.7 passes a NULL value in one of the SAMBA message headers. Obviously, this is a problem for the Celerra. No word as to how gracefully Windows file server handle this issue.