StableBit DrivePool 1.2.1 BETA is now available for testing.
Get it here: http://www.stablebit.com/DrivePool/Download
What’s New
DrivePool 1.2.1 BETA is purely a nuts and bolts release.
No new functionality has been added from the user’s perspective, but it is still a very important release because it makes some fundamental improvements in the reliability and performance of real-time file size tracking, which is the backbone of the new balancing system introduced in DrivePool 1.2.
The old system was pretty fast, but it had some accuracy issues because it was very difficult to “synchronize” between the kernel and the user mode service, two very different components.
DrivePool 1.2.1 is a complete rewrite of the file size tracking sub-system, and it now works entirely in the kernel with no interaction form the user mode service. This means that it is synchronized with the file system directly.
This is all techie stuff, but what this means is that file size tracking is going to be faster than ever and very accurate.
Why Measure File Sizes?
The  balancing system in DrivePool 1.2 is designed to instantly know when your pool needs to be re-organized. When I say know I mean that it doesn’t have to scan every file on the pool to find out. It does this in tandem with the file size tracking system, which informs it of the pool’s organization instantly.
If your pool needs to be re-balanced, based on the rules that you set up or the default rules, the balancing system knows of that instantly. In order to accomplish this, it needs to know the overall distribution of files on the disks that are part of the pool.
Folder Size Measurement
Prior to DrivePool 1.2.1, in addition to tracking the distribution of files on the pool, DrivePool was also tracking the distribution of files per-folder and per-drive.
DrivePool 1.2.1 will no longer track folder sizes in real-time. The only time we use these statistics is in the Dashboard.
This doesn’t mean that we will loose any statistics in the Dashboard, they will simply be calculated for you at the time when you need them.
DrivePool Folders Tab
The folders listed in the DrivePool tab are now queried using Windows Search. The Windows Home Server 2011 already indexes all the shared folders, so we use this index to build a bar chart of how big each folder is.
A small change here is that the folder size is now the total size of all the files in that folder, as opposed to how much space that folder is taking up on the pool. This means that duplicated folders will show their file size, not the on-disk size (which would be doubled).
Re-indexing
In addition, you now have the option of re-indexing the entire server from the DrivePool Folders tab. Again, this has nothing to do with DrivePool but Windows Search. DrivePool is simply providing a convenient interface to it.
File Distribution in a Folder
In DrivePool 1.2, selecting a folder would bring up a small chart on the bottom right showing you the distribution of your files in a pooled folder over the disks in the pool. This changes slightly in DrivePool 1.2.1. We still show you the same information, but it is now measured for you at the time that you select the folder.
Conclusion
All in all, this is the best version of DrivePool yet. It has a faster and more reliable file size tracking system to complement the new balancing framework.
Unfortunately, this means that DrivePool 1.2.1 is going to remain in BETA for a few weeks longer, but in the end the improvements will be worth it.
What’s Next
DrivePool 1.2.1 is feature complete. No functionality changes will be made to it, only fixes from this point on. Once the BETA is tested publicly, it will go out as a release final.
DrivePool 1.3 BETA is almost ready to go, it was being worked on in parallel and is coming along quite nicely.
Here’s what it will look like:
As you can see, the user interface changes are minimal. This is on purpose. We’d like to keep things as simple as possible. But much of the back-end has been revamped to support multiple pools. DrivePool 1.3 has all-encompassing multiple pool support. This means, among other things, that each pool has its own balancing settings. So you can create a few pools, each with tailored file placement and organization rules to your liking.
You should see a public BETA of multiple pool support in DrivePool 1.3 in the coming weeks.