Concurrent hits limitation

[sthaug at nethelp.no]

> We are going to update the RAM to 6 gb and no battery backed cache is configured.

Well, unless you use the RAM as a "RAM disk" (and ensure that you have
stable, uninterruptible power for your server), 6 GB won't help you
for the simple reason that dhcpd does an explicit fsync to commit
leases to disk, and expects the leases to be on *stable storage*
(unaffected by power problems etc) on return from the fsync operation.
You certainly don't need 6 GB of RAM to hold 200K leases.

> > I find it hard to believe that you'll see 5000 DORAs per second, unless
> >all of your clients come online at the same time. Do they?
> 
> Right now we have 48000 active clients, and i am wonder what would happen after the downtime, when lots of hits will come at the same time. Right now approx 250 concurrent connection (showing in the LB connection established option) are there for the bootps. 

What do you mean by '250 concurrent connection'? Do you have 250 DORAs
per second, or do you mean something else?

Steinar Haug, Nethelp consulting, sthaug at nethelp.no