Update Debian Wheezy to Jessie and ISPConfig 3.0.5 to 3.17

Hi,
I want make big and long waiting update Debian and ISPConfig (with billing module) - is this safe? Are there any problems that can happen?
I have about 750 sites on this server and some custom PHP versions (probably must be recompiled after upgrade?).

 

Updating ISPConfig is in my experience easy and does not pose problems.
However, updating the underlying operating system is a chore. After You update it according to the manual, You should do all the installation and setups that the Perfect Sever guide for ISPConfig on Jessie says. This is laborious and involves troubleshooting.
Another possibility is to use ISPConfig Migration tool. This way install first an empty server following the Perfect Server guide. Then run the migration tool on the old servers and do stuff that it asks to do. Read the instructions beforehand and practise once on some test server.

 

Thank you, maybe migration is a good solution... especially I use failover ip for this server. Then there will be an update to a better server too.

 

update from wheezy to jessie
update ispconfig with reconfigure services
login into ispconfig and use tools->resync to resync all websites

you may need a new version of the billing-module

 

Thanks Florian. I decided to use the migration tool. New billing module already bought, new serwer is ready too.
Now I'm testing migration.