EV upgrade to 11.0.1 - estimated downtime

My suggestion is like gertjans but just install ev on One server and do the database upgrades on that one Then if something bad goes wrong and you have to roll back, you only have to reinstall the ev binaries on one server as opposed to all of them Also run a deployment scanner sometime before you do the upgrade to make sure that you have things like the right versions of net framework, powershell, the right services enabled etc But the way that i did my last upgrades were 1. Copy the ev11 sp1 and chf1 binaries to all servers 2. creste an EVSQ directory in a location with plenty of space and excluded from AV 3. Stop and Disable all EV services on all servers 4. Upgrade the first server to ev11 sp1, reboot if necessary, the services will remain disabled 5. Update the SQL script if you have done pst migrations previously 6. Backup your EV databases (audit, directory, monitoring, vault store, vault store group etc) 7. Run evdatabaseupgrader through a command line (if you double click it, it will close the command window) -- services can remain disabled 8. Update the EVSQ location via SQL 9. Install ev11 binaries on each other server -- reboot if required 10. Install ev11 sp1 chf1 on all servers 11. Change the services on all from disabled to automatic 12. Start the Admin and directory service on server1 and wait for the event saying directory do upgrade complete 13. Then start admin, directory and storage on all servers, and await the storage upgrade complete 14. Then start shopping, task and indexing on all servers Then test. For me with about 12 servers in one of our sites it took about 2-3 hours, but there can always be small things that slow you down like someone with a SQL management studio open and a db can't go in to single user mode Or someone has event viewer open so evrt.dll is locked etc