Lowering your DNS TTL before a migration is the single step that turns a nervous cutover into a quick, clean switch. It costs nothing and takes two minutes, but it must be done in advance to work. Here is why and how.
TTL (Time To Live) tells the internet how long to cache a DNS record before checking again. A typical A record has a TTL of 3600 seconds (one hour) or longer. That means after you change the record at cutover, some visitors keep hitting the old server for up to that long - the cache has not expired yet.
If you drop the TTL to 300 seconds (five minutes) a day ahead, then when you finally change the record, the whole internet picks up the new server within about five minutes instead of an hour or more. Downtime during the switch effectively disappears.
At least 24 to 48 hours before the migration - longer than the current TTL - edit the A record (and any records you will change, such as www and MX) in your DNS zone and set the TTL to 300:
Type: A Host: @ TTL: 300 (lowered from 3600)
The advance notice matters: the old, longer TTL has to expire from caches before the new short one takes effect. Lowering it an hour before cutover is too late.
Once the new server is confirmed working and DNS has fully switched, raise the TTL back to 3600 or higher. A longer TTL is slightly better for performance and resilience day to day; the low value is only useful around the migration itself.
Every SoftSys managed VPS plan includes free migration, and our team manages the TTL schedule and the cutover timing with you so the switch is invisible to your visitors.
