On Fri, Jun 15, 2012 at 07:02:07AM +0200, Otto Moerbeek wrote: > On Thu, Jun 14, 2012 at 01:54:33PM -0500, Tristin Davis wrote: > > > Upgrading is simply not an option. It all comes down to having the > > engineering staff, money, and downtime available. Unfortunatly, we have > > none of the above right now. I realize we *need* to upgrade, but right > > now, tuning the kernel is the only option.
You could have minimal downtime if you had a spare machine to install 5.1 on and set everything up the same, then do something like this: 1. 4.3 machine: kill sshd 2. (optional) wait for existing ssh connections to 4.3 machine to drain 3. unplug ethernet cable from 4.3 machine 4. bring up CARP interface with the old 4.3 IP address, on 5.1 machine Now you have it running on CARP, you can setup a failover system as should have been done originally. Your limited time is probably better spent doing this, rather than messing around with archaic tuning options.
