I received a notice last week that my VPS hosting at 1and1 was on 'old infrastructure' and I'd have to pay an additional $5/month starting in April, 2019 for the 'extra' support it required. Hmmm... since I'd been bucking against the limits on that VPS (acquired in 2016), I decided to plunge with a new Cloud VPS contract and do the porting of 20 domains/12 websites to a new VPS.
Old system was Virtuozzo/Plesk , CentOS6, 2 CPU, 2GB RAM, 143GB HDD. Apache/Ngnix, PHP 7.2.15
New system is VMWare/Plesk, CentOS7, 4 CPU, 4GB RAM, 160GB SSD, Apache/Ngnix, PHP 7.2.15
Fortunately, Plesk had a 'Migrate Sites' plugin which made the move of the configs/site contents painless from old to new server.
Then the fun began... I had to update 20 domains to point to the new server (one at a time). That all worked.
Had everything running on the new server (and no traffic left on the old server) so began transferring the domains from one ionos contract (old) to another for the new VPS. That worked too, BUT.. they thoughtfully reset the IP address to the old VPS as they changed which contract it was applied to. Back again through the domains changing the IP address to the new server.
Wait another day for the traffic to go to zero on the old server and shut down all the old cron jobs.
Had some issues on the new server caused by my renaming the primary host from the default system name of the old server to a new name so I could install a Lets Encrypt cert for ssl. That also changed the filesystem path to httpdocs with that new name, so a series of cron job scripts had to be changed. Also, the new server refused to emit mail messages for a while.. that required 3rd level plesk support to finally fix so mail was now working as it had on the old system.
Total time elapsed was about 4 days for completion. I did avail myself of the Personal Consultant hotline several times during the conversion to fix some arcane issues.
The extra headroom provided on the new VPS meant I could enable Fail2Ban and Apache mod_security to better secure the sites (the old server griped about insufficient resources when I had Fail2Ban operational).
In all, I'm satisfied with the support I'd received and the functionality of the new VPS/management system and look forward to some smooth running of the Saratoga/regional network sites I host.