Hello Mousa,  Along with the environment checks mentioned above you need to make sure that the correct sequence of upgrades is followed.  EMC began to support only one-level migration, which began with FOS v6.0.0, as it provides more reliable and robust migrations for customers. By having fewer major changes in internal databases, configurations, and subsystems, the system is able to perform the upgrade more efficiently, taking less time and ensuring a truly seamless and non-disruptive process for the fabric.  So upgrading to Fabric OS v6.3.0 is only allowed from Fabric OS v6.2.0 or later and so forth.  Hence the suggested upgrade path would be 5.x => 6.0 => 6.1 => 6.2 => 6.3 for best practice.  Kindly find attached the release notes for all 3 OS versions. The release notes contain very useful information about how to upgrade, fixed problems from previous versions, known problems and limitation, and an overall general synopsis of the new OS.  Note: As firmware 6.0 is now archived, you will need to send an e-mail to EMC_GS_Web_Request[NAME].com requesting the code along with the release notes.  I hope this answers all your questions, if you have any other questions/problems please let me know.  Have a great day.
Hi I will upgrade FOS from 5.3.0 to 6.3.0b for a fabric have  two ED-48k one on main site and the other on DR site with ISL link  between them my environment is heterogeneous to the max what  should i check before starting the upgrade i will check HBA  FW , Driver PowerPath what else should i check and  what the procedure for the whole process what the risk ??????????????????? >>>>>>>>>>>>>   Many Thanks     [IMAGE]Don't tell me the sky's the limit when there are footprints on the moon [IMAGE]
FOS upgrade