systec.blogsite.org

First – all systems are up and running! It is always exciting to make changes in productive environments because testing in a test environment is a bit “sterile” or “artificial”.

The resize operations on VMWare were straight forward as always but it took some time to backup the virtual harddrives before.

The really interesting thing was to shrink the ext3 partition on one of our OpenVZ servers, lvreduce the LVM logical volume, grow the ext3 to the maximum of the resized LVM logical volume and to implement DRBD for productive usage between to hot servers. Result: perfect! I decided to push up the syncer rate of DRBD (default 240K/sec.) to 20M/sec. The initial primary/secondary sync took about 30 minutes (20 G device).

Today the status is that the DRBD devices are in sync and the nighly reboot of the servers had no impact. I think I will make a little .deb package today for my management scripts of the OpenVZ containers (stratup). After that time is coming to copy our loadbalancer into the DRBD…..

Mario

Today I found the time to write a documentation (in German language for our work) about DRBD, a network (block device) based RAID 1 system. My target is finding a way to use normal LVM based devices and DRBD based devices in synergy on one host. Why? We have the requirement to build some containers fail save but not all. This means that we have an important central Apache based load balancer an some Tomcat based application server which we like to be online mirrored to another OpenVZ hardware node and if it is possible we will try to mirror over WAN from Austria to Germany.

I guess we will update the existing DRBD-OpenVZ wiki page which is a little bit outdated. Maybe I think we will contact Werner Fischer who we knew from the LinuxTag09 and who is the author of the wiki page.

In fact I learned a lot today and I also tested some scenarios (split brain, switch over,…) that make me think positive that it could work.

Stay tuned because I will post the translated documentation (German -> English) from our workplace at http://systec.blogsite.org/wiki.

Mario