[CentOS] High-Availability Clustering and drbd?

[Andrew Cotter]

> -----Original Message-----
> From: centos-bounces at centos.org [mailto:centos-bounces at centos.org]On
> Behalf Of Johnny Hughes
> Sent: Friday, March 17, 2006 3:31 AM
> To: CentOS ML
> Subject: Re: [CentOS] High-Availability Clustering and drbd?
>
>
> On Thu, 2006-03-16 at 23:52 -0800, Benjamin Smith wrote:
> > Ugh. What a week!
> >
> > Anyway, my situation is that we have a production server in San
> Fransisco, and
> > a "hot" backup in my hometown (Chico, CA) .
> >
> > What I'd like to do is mirror the production server to the
> local one, so that
> > if the SF server goes down, we have work saved to the last
> possible moment.
> > Say, within 10 minutes.... Is this feasible?
>
> I don't think something like DRBD is going to work very well across a
> WAN link.  The amount of traffic generated by drbd can be pretty large,
> it is enough that I normally use a gigabit crossover cable between 2
> servers (if possible) when using drbd on them.
>
> I would think that rsyncs of the appropriate directories at a period in
> time might be the best way to handle this.
>
> I am getting ready to do this in then next week or so myself ... if I
> have any luck, I'll tell you what solution I found.  In my case I am
> also worried about a mysql database that has live info in it ... and an
> ldap database too.
>

Good to know the bandwidth requirements of DRBD before trying it over our
WAN.  We use rsync to keep a directory structure in sync with a backup
server on the other side of the contry.  In total the directory is about
34GB and consists of images of scanned documents ov verious sizes.  We shoot
this over a T1 across the US and once the original sync is done, it does a
nice job a couple times a day checking and updating differences.

I have also played with Unison (http://www.cis.upenn.edu/~bcpierce/unison/)
with some success, but ended up using rsync for another project.

As for MySQL over WAN, how have people done with the built in replication?

Andrew