Date: Mon, 6 Feb 2012 12:54:49 +0200 From: George Kontostanos <gkontos.mail@gmail.com> To: freebsd-fs@freebsd.org Subject: HAST considarations Message-ID: <CA%2BdUSypg_3uNYMtU2tnvrvAPFw8MjM596tDZ=R_eqpE=GL1-=A@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Greetings list,
I have been experimenting with HAST on a raidz ZFS pool and I have
stumbled upon some issues. So, any suggestions are highly appreciated
:)
My testing environment is consisted of a Linux KVM machine with an
Intel Core2Duo and 4G RAM with 2 SATA drives striped (for performance)
since I don't have the metal to experiment.
When someone is considering to use a HA solution for storage then I am
quite sure that their set up would include redundant switches and
NICs. For best performance the HAST synchronization should be
independent from the CARP interfaces, possibly consisting with more
than 1 NIC with lag. At least that's what I think.
The first problem appeared when trying to setup the resources. It
seems that the resource name is tight up with the machines hostname.
My hast.conf looks like this:
resource disk1 {
on hast1 {
local /dev/da0
remote hast2
}
on hast2 {
local /dev/da0
remote hast1
}
}
resource disk2 {
on hast1 {
local /dev/da1
remote hast2
}
on hast2 {
local /dev/da1
remote hast1
}
}
However, the hostnames are storage1 and storage2 with storage being
the shared CARP IP. Both hast1 & hast2 resolve in /etc/hosts and are
connected to a different private vlan but when trying to create the
first resource the system complained that only hast1 is an acceptable
resource name.
After changing both machines hostnames I was able to create the
resources and a zpool mirror consisted upon /dev/hast/disk1 &
/dev/hast/disk2
Manual failover also worked by exporting the pool from the master,
switching roles and then importing the pool on the slave. Yet, looking
at the example scripts I realized that there is a lot of work to be
done since automatic failover is based upon the CARP device and is
limited to one resource. I replicated the resources at the script
level in order to switch roles for all the devices. Still it looks
very basic and crapy.
Also, I added the NIC witch is being used for HAST replication to the
/etc/devd.conf besides CARP
I see this being at an early stage but I was wondering if anyone has
to share some success (or not) stories. Also, does anyone else share
my point regarding separating CARP and HAST replication? If yes I
would be very interesting to know how this was done.
Regards
--
George Kontostanos
Aicom telecoms ltd
http://www.aisecure.net
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2BdUSypg_3uNYMtU2tnvrvAPFw8MjM596tDZ=R_eqpE=GL1-=A>