Important info for LVM-on-DRBD users added to User’s Guide

My former employer has managed to roll a fresh build of the DRBD User’s Guide. This contains an important addition to the chapter on LVM: when running LVM on top of DRBD (that is, a DRBD device acting as a Physical Volume to an LVM VG), don’t forget to update your initrd after modifying your LVM filter configuration.

This is something that many users tripped over previously, so I’m happy to finally see it available in the published Guide.

There are several other additions and fixes currently pending, so I’m hoping they will publish those soon, too.

Updated OCF Resource Agent Developer’s Guide now available

I have just published an updated OCF Resource Agent Developer’s Guide. This guide is the definitive handbook for authors of, and contributors to, resource agents for the Pacemaker based Linux High Availability stack.

Asterisk High Availability coming to the Pacemaker cluster stack

The Pacemaker based Linux cluster stack is gaining a freshly supported service: the Asterisk open-source PBX. hastexo‘s Martin Loschwitz has contributed a resource agent for the popular telephony stack.

Now available: Slides from Percona Live and Linuxcon Europe

The slides from last week’s talks I (co-)presented at Percona Live and Linuxcon Europe are now available from our web site.

• In my tutorial MySQL High Availability Sprint: Launch the Pacemaker, I gave a fast walk-through of Pacemaker high availability for MySQL. Tutorial presented at Percona Live UK 2011 in London, England.
• In Fencing and Maintaining Sanity in High Availability Clusters, Madison Kelly and I explored the importance of fencing in HA clusters, highlighted important considerations for fencing, and shared technical details and best practices. Talk presented at Linuxcon Europe 2011 in Prague, Czech Republic.

All slides are available entirely free of charge for logged-in users on our web site. To log in, you don’t even need to register — just use your Google Profile, or Google Apps account, or your WordPress account, or anything else that uses OpenID, and you’ll be good to go.

Comments on our slides are, of course, always highly appreciated.

Running DRBD on your Android

So you own an Android phone? I do too (mine is a Samsung GT-I9000), and it doubles as my Twitter client, guitar tuner, Ultimate rulebook and a ton of other things. And of course, I’ve DRBD’d it so I can sync everything on it to a logical volume on my desktop. You do know that DRBD can run a mixed-architecture cluster, so syncing from your ARM-based handset to your x86 (or x86_64) laptop is no problem at all.

How to do that? Not that hard. First, obviously, root your phone. Then, download DRBD off the Market.

You’ll need BusyBox and some way to get a shell on your phone. I prefer ConnectBot. And from there? As you normally would. Just use drbdadm (the -c flag may come in handy for non-default drbd.conf locations) Set up a logical volume on your laptop, sync, and poof you’ve got your phone backup. Then, just disconnect or stop DRBD on your laptop.

Hint: if you use Advanced Task Killer (I do), make sure to put the DRBD app on the ignore list. The Android build has a special #define enabled that has DRBD wait patiently for incoming connections, but not initiate outbound connections to its peer. This also means that DRBD won’t mind at all if you suspend your phone. Just don’t kill the app.

A full Tech Guide, “Running DRBD on Android”, is available from LINBIT’s web site. The QR code at right will take you just there. No QR reader app? Try Barcode Scanner.