Upgrading unRaid cache to btrfs

Having upgraded to unRaid 6 beta7, I've started having a look into the new Docker support. In unRaid, Docker needs to be installed on a btrfs volume or pool. Btrfs is a new filesystem to unRaid and supports 'copy on write' which enables Docker utilise minimal hard drive space. (see the Docker intro thread on unRaid forms for full details.)

My existing cache drive was a seagate 500GB and contained all my VM images and config files in a 'domains' directory. I copied these files off to a backup drive and set to work.

It was a good thing I made a backup as it soon became apparent that it would be very easy to make mistakes and wipe a lot of data!

unRaid 6beta7 Update

The next beta of unRaid is out about a week and today I got around to installing on MediaServer8. I'd been on beta5 for some time as there was a problem in beta6 that prevented the Marvell SATA controllers on my motherboard working. Happily, this is now fixed in beta7.

I'd made a few adjustments to my TVServer Win7 VM to reduce the RamDisk size. Happily, on reboot, the RamDisk re-instantiated and the timeshift user share for activated automagically. This had been once concern for me - how would the RamDisk behave on VM restarts. Perfectly, as it turns out.

So this is all good news. I can now start playing with the new Docker features of unRAID and start thinking about whether Xen is the correct VM platform as KVM is now an option for me.

Ramdisk for Timeshifting

I've added an extra 16GB of memory to MediaServer8 to now give a total of 32GB.

This has allowed me increase the assignment of memory to my Windows7 TVServer VM from 4GB to 16GB.

I want to experiment with using a ramdisk for timeshifting rather than a physical disk. A ramdisk is a virtual disk that exists only in memory. The advantage is that it's superfast, the disadvantage is that the contents are destroyed on each restart. However, this is not a big deal for timeshifting as there are only transient files stored.

For me, using a ramdisk rather than a physical disk also means that I can remove the 75GB Raptor I've assigned as a timeshift drive, freeing up the SATA port and physical bay for another storage drive. So all in all, it should be win-win.