Upgrading MythTV to Mythbuntu 12.04 64-bit

As described in the previous post, the time had come to upgrade my MythTV installation. It had been installed using Mythbuntu 10.10, 32-bit. I wanted to move to the most recent version, currently Mythbuntu 12.04. There were two options available to me: upgrading the current installation, or a new install of the latest version, and copying the previous MythTV database over to it. The first option was not too appealing. Doing a distribution upgrade is a fingers-crossed, hope-this-works process a good part of the time - although I have had pretty good fortune with it on my desktop PC. If I were to go this route, I couldn't just upgrade from 10.10 -> 12.04. It would have to be 10.10 -> 11.04 -> 11.10 -> 12.04. Three complete system upgrades in succession, which would likely leave a lot of cruft left over in the installation. Lots of points of failure. The final nail in the coffin was that I wanted to move to a 64-bit installation, to take advantage of the full 4GB of memory that was installed in the system.

So a clean install it was. To prepare, I copied a number of setup files to a safe place that wouldn't be overwritten during the install. Files like:

• mdadm.conf, from /etc/mdadm, which had the RAID configuration information. 
• xorg.conf, from /etc/X11, which had the custom modeline used to output to my (now ancient) CRT TV. 
• ssmtp.conf, from /etc/ssmtp, for email notification in the case of errors.
• apcupsd.conf, from /etc/apcupsd, the setup of the APC UPS monitoring software.
• hardware.conf, from /etc/lirc, used by LIRC to set up the Media Centre remote control.
• the MythTV database password, from /etc/mythtv/config.xml

Not all the files would end up being needed, but I felt safer having them handy, just in case.

The installation process started from a USB stick loaded with the Mythbuntu 12.04 installer, since I don't have an optical drive in it. No room, with three drives already there. I also hooked up a monitor instead of a TV, because that needs extra setup to output to a component connection.

Since there was some left over free space on the SSD, I installed to that, leaving the 10.10 install intact for now. It went remarkably smoothly. One thing I noted was that at the beginning, there is an option to update the installer. I clicked that, and the system seemed to do nothing for quite a while. Opening up a terminal window and running "top" showed that it was in fact doing something, so I waited until it finished. Once done, the installation process could begin. It would have been nice for it to have some sort of indication that it was doing something, though.

Partway through the process, it prompted for what sort of remote control is being used. I selected "Windows Media Center remote", and the thing was set up automatically. Brilliant! Didn't need that LIRC setup file listed above.

To get the system outputting to my TV properly, I just copied the old xorg.conf file to the /etc/X11 directory (I renamed the existing file, in case I needed it again) and rebooted with a sense of hope and anxiety. A minute or so later, the screen came to life! It worked!

The big one, that I was dreading, was getting the RAID array to be seen by the new install. I still consider myself quite the mdadm novice, so I was pleasantly surprised to find that the RAID array was picked up by the new install quite easily - after installing mdadm and lvm2. This command:

sudo mdadm --assemble --scan

was all that was needed for it to scan for any drives, re-assemble the array, and write a new mdadm.conf file. Easy!

Next was seeing if LVM could find the volumes created. Running

sudo lvm pvscan
sudo lvm vgscan
sudo lvm lvscan

detected all the physical volumes, volume groups, and logical volumes, respectively. Mounting the logical volume that held the recordings was successful - I could see them all. Adding the device entry to /etc/fstab seemed to work, eventually. On the first reboot it came up with an error message, mentioning there were serious problems with the mount. Not sure what it was, but a reboot afterwards seemed to make it happy. I had installed xfsprogs, to manage and defragment XFS filesystems; maybe that helped.

Going through some of the MythTV screens brought up some error messages that it couldn't write to the drive - it turned out to be a permissions issue for the files and directories on the array. Entering

sudo chown -R mythtv:mythtv /var/lib/mythtv

changed the ownership back to the mythtv user, and it seemed happy again.

Bringing the previous database over was a painless process as well. I followed the instructions here and here and the new database came over without drama.

So far it all looks good. I may have a tweak of the VDPAU settings to see if playback can be improved any - it looks fine, but the settings have just been carried over from the previous 0.23 version. Things may have changed in the current 0.25 release.

Now that the system is updated to 12.04, which is a Long Term Support (LTS) release of Ubuntu, I won't be caught out with an obsolete version after 18 months like I was with 10.10.

As a side note, one of the main reasons for moving to 64-bit was because the Zotac IONITX-A-U motherboard, with an Atom 330, was only showing 3GB of RAM installed, even though I had two, 2GB sticks in there. I thought this was a 32 bit software issue. After installing the 64-bit OS, the free memory remained the same. Even in the BIOS, it only reported 3072MB. Strange. A bit of searching around revealed this thread on Zotac's supprt forums. As it turns out, if 4GB is installed, 512MB is reserved for system use, and then there is the amount used by the onboard Nvidia ION graphics - which I had set to the maximum allowed 512MB. So only 3GB visible. It's OK, it still runs fine, but it would have been nice to be able to use a little extra.

My MythTV system - the story so far

For the past 18 moths or so I've been running a MythTV system in the lounge, which has been an excellent performer. It has liberated us from TV advertisements and from having to be home in time to watch a particular show. It has been slowly enhanced and upgraded over that time to be quite a capable machine, exceeding what could be purchased from a store.

Following on from one of the earlier build posts, one thing done was purchasing a larger wireless antenna. For under $20, it allowed the antenna to be moved to a position with better reception to the wireless router, and with a stronger signal. There have been very few connection dropouts since putting that in. The eventual goal is to have a hard-wired ethernet connection, but that will be some time down the track if I ever get the house wired up for it.

Another issue was with a hard drive upgrade. Originally with the 2TB Samsung disk, I upgraded it to a Hitachi 5K3000 3TB drive. It ran well for about three months, but then I came down to the lounge one morning and the system wasn't happy. There were drive errors of one kind or another. I grabbed the 2TB Samsung drive again (which had been serving a happy retirement in my desktop PC), and luckily was able to copy all the recordings over to it. It was fortunate that I hadn't filled the extra space either.

So the system was back to its original storage drive, until the warranty fix came back from Hitachi. About three weeks later, a replacecment drive showed up - this time it was a 3TB 7K3000, the next model up. Also, since this happened after the Thailand floods, one of those drives was now worth nearly $400, quite a bit different from the ~$160 I paid.

Now I had a refurbished 3TB drive and a 2TB drive with a year's heavy usage already on it. This made me a little nervous. It was time to move to a RAID1 system. I used the linux mdadm software RAID, with some LVM volumes on top of it. It is a while back now, but the install went OK I can't quite remember the tutorial I used, but these two have quite a lot of information on doing so. The performance hit from running RAID and LVM was not noticeable on the system, either. If desired, you can also set up email notifications if a drive fails or some other problem arises with the array - see here, here and here. One thing to note if you use gmail to send the notifications: if your password has a "#"in it, ssmtp will read the rest of the line as a comment and you'll get all sorts of strange errors. Oh yes, it's best to set up a secondary gmail account to do this, with nothing important in it, since you have to keep the password in a text file.

Since the system worked well, I didn't bother with updating it. It wasn't open to the wider internet (to access via MythWeb). But it was time for a change, and Mythbuntu 10.10 was no longer supported. It was time for an upgrade to a newer version - which will be detailed in another post.