From: Wray Cason (wrayman_at_auxiliumcomputing.com)
Date: Sat 03 May 2003 - 10:55:04 BST
> > > > > I use the vserver patch together with a Raid1+DRBD/Heartbeat failover
> > > > > config. If the primary server fails all vservers are started on the
> > > > > secondary within a few seconds. Besides the recently fixed bug in
> > > > > ctx15/ctx16 this setup is 100% stable.
> > > >
> > Very interesting. Is there any write-up available for this solution? I am
> > eager to learn more about the specifics.
> I don't know one which describes the whole setup. There are
> howtos/docs on DRBD+Heartbeat (try Google).
> Basically my setup works like this:
> Heartbeat Setup
> BoxA and BoxB are monitoring eachother over ethernet (udp/ethX) and
> DRBD Setup
> A pair of servers (lets call them BoxA and BoxB) share two DRBD
> (drbd0, drbd1), which map to a local lower level block device. If
> both servers are up, one DRBD device is primary (=write access) on
> each server:
> - drbd0: primary -> (maps to /dev/hdXX or /dev/mdX or whatever)
> - drbd1: secondary
> - drbd0: secondary
> - drbd1: primary
> All changes to a primary device are replicated to the other node.
> (On most servers I use a local software raid1 device, which means
> that the data exists on four physical disks).
> VServer Setup
> /dev/drbd0 is mounted as /vservers-BoxA (if it is primary)
> /dev/drbd1 is mounted as /vservers-BoxB (if it is primary)
> in /vservers there is a symlink to /vservers-Box? for each vserver
> BoxA fails:
> 1. Heartbeat on BoxB notices BoxA isn't there any longer and starts
> taking over resources.
> 2. DRBD (actually the datadisk script as specified in the Heartbeat
> resources file) takes over drbd0 and mounts it:
> - drbd0: primary
> - drbd1: primary
> Now both /vservers-BoxA and /vservers-BoxB are mounted on BoxB.
> 3. Heartbeat starts BoxA's Vservers on BoxB.
> > I gather that one important point
> > to consider is the fact that the vserver kernel doesn't support journaling
> > file systems.
> Are you talking about the precompiled kernel? I never used it.
> I use both reiserfs and ext3 on drbd on raid1 with the vserver patch
> without problems.
Very good stuff, much thanks.
-- Wray Cason "Wrayman" Auxilium Computing www.auxiliumcomputing.com wrayman_at_auxiliumcomputing.com main: 206-595-2080 fax: 425-895-9825