Over the past several weeks the question regarding RollBack Rx and how it works with SSD TRIM has seen resurgence. While the question was originally asked and answered in 2013 in this thread (when SSD’s were becoming more adopted by the mainstream population), it has come to our attention that more technical answers are sought after to explain how and why RollBack Rx works with TRIM.
A little history
Around 2011 SSD’s were starting to become a viable purchasing option for businesses and home users alike, including RollBack Rx owners. TRIM, the SSD equivalent of Windows defragmentation (as it acts as a garbage cleanup function), was also starting to come out the woodwork. At this time, our older version of RollBack Rx was tested on an SSD with TRIM enabled, but it could not be functionally installed and the software had to be patched to work with SSD’s with TRIM enabled. This was done, and is still the case.
How RollBack Rx works with TRIM
In November 2013, this explanation was posted in this forum thread regarding Windows defrag and SSD TRIM:
Question: Does RollBack Rx support SSD TRIM
Official Answer: Yes, it does. RollBack Rx has to support TRIM due it its architecture.
2nd Question: How come this is different from what I see when using TRIM check and other utilities?
Answer: You need to understand that RollBack Rx fundamentally changes the “view” and “perception” of disk usage. On a system without RollBack Rx, the disk sector allocation is “black and white” (used or unused – absolute), there are used sectors and there are unused sectors. What you see is exactly what it is (binary).
On a system with RollBack Rx installed, the disk sector allocation is much more complex and “colorful” (then black or white only). These are what RollBack Rx calls used sectors and unused sectors. But the used sectors can belong to multiple/various snapshots. A sector can be used by snapshots 25, 26 and 27. The most intriguing part, is when you are in snapshot 20, that sector could appear unused to the system. What you see is not what it actually is. So continuing with the example above, when you run disk diagnostic tools (TRIM) or defragment tools in the snapshot 20, you will not be able to make a correct judgment for that sector (you see it as an unused sector but that is not the case). If it’s not seeing the sector usage correctly, how can it make a correct judgment based on the wrong information? This is why we don’t recommend users to run disk defragmenter tools or rely on SSD TRIM apps after installing RollBack Rx. It is not that these apps will damage RollBack Rx, but because they are not going to provide you with a clear and accurate picture of what is going on.
With regards to defragmenter we recommend uninstalling RollBack Rx or at least updating the baseline once you have completed defragmenting. With SSD TRIM utilities that work from within Windows you will not get an accurate read on TRIM.
I hope this information helps clear the air and provide a better understanding of the RollBack Rx technology and its relationship with Defragging and SSD tools.
This answer has not changed, but we believe additional clarification is needed as extended testing has been done internally and externally.
Here’s the test that was run and the findings.
- Installed RollBack Rx on a fresh machine.
- Took a snapshot of the clean state.
- Ran a batch script to fill up drive space.
- Checked the sectors to confirm space usage.
- Took a snapshot of the system with filled space.
- Rolled back to fresh snapshot.
- Ran TRIM.
- Checked the sectors. Confirmed sectors still in-tact following TRIM, as data space usage is protected by other snapshot.
- Deleted snapshot with disk space usage on it.
- Defragged inside of RollBack Rx.
- Ran TRIM.
- Checked the sectors. Confirmed they are still in-tact following TRIM, as data space usage is still protected by RollBack Rx as another recovery failsafe for a time.
- Uninstalled RollBack Rx.
- Ran TRIM.
- Checked sectors. Space was recovered and cleaned.
The part that requires further explanation is Step 12 as the natural question that follows this is, “If RollBack Rx’s snapshot with the data on it is gone, why is that sector unaffected by TRIM?”
RollBack Rx is all about layers – creating snapshots that store and protect data on the sector-level of the drive. However, sometimes it’s necessary to uninstall RollBack Rx or reset the Master Boot Record (MBR) in order to have a full recovery following a catastrophic event. Yet, some of you may be familiar with the fact that even after an MBR reset is done and the system is put back to the point when RollBack Rx was first installed, that it is possible to still recover data and pull up snapshots stored on the drive.
That is due to an additional security layer made by RollBack Rx. Even after the removal of the software, there is a time left available to those sectors RollBack Rx was protecting where it’s possible to access them and restore your data. That time is limited, and without immediate action will soon be written over or, in the case of TRIM, remove the data once it runs*.
RollBack Rx still works with TRIM, and vice versa. But, as with all garbage cleanup utilities, it is hard to get an accurate reading of the drive as RollBack Rx will take over and redirect incoming TRIM commands to other sectors to ensure the integrity of the software, and the data, is not compromised until fully available.
We’d like to particularly thank our dedicated forum user Froggie for not only his extensive testing, but his time spent with our technicians and his write-ups on the matter.
*In certain cases, those sectors are still protected from the automated TRIM function for a time, but if manually run by Optimizing the disk, it will reset the sectors.