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>