By major upgrade, I was referring to when we went from 2.2.4 to 2.3.1 in April 2010. They rebooted all the of odd nodes at one time, which scared the heck out of me, but was working as intended.
Their health check prior to the upgrade specifically surveyed and flagged any hosts that were "vertically attached" for the purpose of ensuring this vertical reboot of all the evens, or the odds did not cause a host outage. We had to correct that in order to proceed with an online upgrade.
Here is the exact verbiage sent from 3PAR support (John Tolnay) on 4/2/2010
Quote:
3PAR Support has reviewed the host information that was supplied for InServ S/N 1202XXX against the attached Configuration Matrix. From the supplied data we cannot support an online upgrade as the configuration does not match the 3PAR support matrix. We do not recommend an online upgrade for configurations that have not been tested. The successful completion of an online upgrade with an untested configuration cannot be guaranteed.
4. The following hosts are attached to vertical nodes.
These connections are not to 3PAR recommendations and may prevent an online upgrade.
Connections have to be changed to horizontally adjacent node pairs.
ID Name --- WWN --- Port
2 R6KXXXQAA 10000000C9464CXX 5:5:1
2 R6KXXXQAA 10000000C9464CXX 7:5:1
14 NTFWXXXSQLD1 10000000C93719XX 5:5:2
14 NTFWXXXSQLD1 10000000C93719XX 7:5:2
18 NTFWXXXMISCPD 10000000C92418XX 5:5:2
18 NTFWXXXMISCPD 10000000C92418XX 7:5:2
That said, perhaps they turn something off or on when doing an upgrade to allow 2 nodes to go down without triggering a panicked shutdown. I, personally believe but do not certify or guarantee, that if 2 nodes from different node pairs died, the system would keep on serving.