On Sat, May 31, 2008 at 7:40 AM, sbeam sbeam@onsetcorps.net wrote:
I have an existing in-production LAMP server running Centos 5.1...
We have a near-identical system I am thinking of bringing in as a DRBD/Heartbeat companion...
Why don't you consider using MySQL master-slave replication? It seems to me that in your case that would be more simple, more flexible, more reliable, would require less bandwidth and would give you more performance than you can get with DRBD. Although DRBD is the latest buzzword and everybody wants to find an use for it, I think it's not the best tool for this job.
DRBD is dumb in the sense that it replicates blocks. If the application that does the replication knows the data, it knows what to send to the other side (record insertions and updates) and what not to (index data, since that will be recreated), and it also doesn't have to send a whole block of data each time you change a few bytes.
If you want automatic failover, you can still use Heartbeat to transform a slave node into master when the master goes down.
You will certainly find several recipes on how to do it on the web.
Just my humble opinion, but I hope this helps.
Filipe