A couple of weeks back, NX-OS 5.2.3 was released for the Nexus 7000 platform. This was the first maintenance release for the long running train of the NXOS 5.2 software train. Unfortunately, almost as soon as it was posted to CCO customers started to incur issues with the upgrade from 5.2.1 to 5.23. One of the scenarios that produced the bug conditions was mentioned on the Cisco Network Service Provider Mailing List (cisco-nsp) – see here for the start of the thread. Cisco TAC quickly responded and has since deferred the 5.2.3 release for 5.2.3a.
Also should be noted that NX-OS 6.0(2) is now available for the Nexus 7000 which is a short runnig train that introduced hardware support for the Fabric 2 modules and F248XP-25 on the Nexus 7010 and Nexus 7018 chassis ( the Nexus 7009 had FAB2 / F248XP-25 support at its FCS on 5.2 ).
What does this all mean? Well, it means you should always be judicious when introducing new software to your production infrastructure as while hardware and software manufacturers will do whats possible for quality assurance, they don’t always take into account all of the variables that can occur in a given customer network. See some of the case examples in this book written by a friend of mine..
the rants of a data center crash test dummy 