Quote:
Originally Posted by streetmedia
both machines are centos linux, with mysql databases. one runs on Virtuozzo whm / cpanel, the other with lxadmin (hypervm). i have the option to have whm / cpanel on both at extra cost.
just taking a look at rsync.
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rsync is very good, but remember you'll always be playing catch-up with changes made to the file system. If you want to be able to switch to your standby VPS and not potentially lose a few minutes/hours (depending on how often rsync runs) of file changes, then you'll need to consider a real-time block replicator like DRBD, although as you might expect this will require assistance from your host to get it set up and certainly isn't a standard requirement, so you'll no doubt be charged appropriately for the host's time and infrastructure changes.
If you're not running a service which absolutely depends upon realtime replication, rsync is a much simpler solution.
The other potential issue is your choice of failover (DNS) - you run the risk of having people caching the old result and then not adopting the new server's IP until their local server chooses to renew the DNS record, which could be hours or days. To guarantee instant failover, you'd need to consider something like VRRP between the two VPSs which will transfer the IP locally. But then you have the problem of the edge router storing the old IP's corresponding MAC address for a while, which will also take you offline. Fun.
