Quote:
Originally Posted by eUKhost.com
You wont face any problems this time as we will move only your account and we will take care of verifying working of all your website hostings after transfer. You wont face any sort of downtime and you wont need to make immediate DNS changes as we will notify you once everything starts running smoothly from the new server. |
I don't think it's quite as simple as that. Based on past experience, DNS propagation causes a couple of issues, once we make the DNS changes...
If a POP client uses the hostname then it may start collecting mail from the new server while some mail is still arriving at the old server - and such mail will effectively be lost.
On the other hand, if a POP client uses the IP address, this will need to be changed. If we wait until propagation has completed before changing the IP address, then no mail should be lost - but some mail may have been waiting at the new server for 72 hours.
To avoid losing or delaying any email, I typically access POP3 servers via IP address then create a new account for the new IP address when a web site hosting is due to move. That way I pull down mail that arrives on either server.
However, I had to to this for my clients when I moved to EUKHost. And I had to do it when my hosting was moved to EuroFighter. So I don't really want to have to do it to all my accounts and all my clients for the third time within a year...
Furthermore, sites with databases cannot necessarily run on both servers at once - as changes made to the database on the old server will be lost on the new server. (Of course, you could copy the database over, but then changes made to the database on the new server would be lost instead!) During propagation, web site hosting visitors may access either server and therefore either web site hosting and either database. To preserve data integrity, one of the databases has to be locked during propagation. This effectively causes downtime for those customers accessing that server. This is a particular issue for ecommerce sites as they lose around 50% of their sales during this time.
Is there any way to avoid these issues, or is some unavailability unavoidable for some web site hosting visitors?