Free space usage problem still not solved...?

chaoscreater · November 27, 2010, 1:10am

Hi all, I need some help here.

First of all, I’ve used CTM since it was first released. There were problems back then and even though it’s a really nice program but it just didn’t work well for me, so i stopped using it. This is about a year ago or so.

Recently, I got back to using it again after hearing good things about it, mainly that all the previous problems/bugs were fixed and it’s working a lot better and more stable now. So, i decided to give it a go once more and I’m pleased with what the development team has done to improve it.

Everything is better now, runs a lot more smooth and most importantly, it worked on all the PCs i’ve installed on without any problems that i used to have. While it works great on my newer PCs, especially the ones that have newer custom built hardwares made for gaming, but on my lower end PCs such as my HTPC, it still has the same problem that introduced in the first version since it came out.

Whenever you take a snapshot, it uses up your free space. However, CTM doesn’t seem to recognize the “ACTUAL” amount of free space you have left on your hardrive. This was one of the main issues for me as i couldn’t take many snapshots, in other words backups. I know many people had the same problem back then as well as I’ve seen multiple forum topics about this at that time. But right now, the problem is still there. Like i said, this isn’t a big deal when you run CTM on higher end PCs, i have like a 3TB hardrive on my main gaming rig so it’s not a problem to me and i couldn’t care less if it eats up say 300GB of space on my hardrive (well i do but not a big deal).

But on my HTPC used for work purposes mostly, where i have a 100GB hardrive which is super small, CTM just doesn’t seem to use more space from the hardrive than it should be. Another problem is, deleting snapshots don’t free up more free spaces, which doesn’t make sense as it SHOULD.

I currently have 1486MB free space left shown on CTM. Yet, I have at least 10GB+ free space left on my hardrive. I deleted all the snapshots and only have 2 now. I also optimized it using CTM’s defragmentation option. I’m planning on doing an actual defragmentation of my hardrive using Smart Defrag or Defraggler, but i don’t think that’s necessary as CTM isn’t recognizing there’re at least 10GB+ of free space left to use rather than the 1486MB it shows.

I’m really happy with the current version and release so far, but if this problem isn’t solved, i’ll end up having to uninstall it like last time as i get popup errors from my other programs about insufficient hardrive space etc etc, but those errors only popped up only after I installed CTM recently. Anyway, isn’t there a way to make CTM increase the free space usage?? It seems to have a limited defined usage rather than take the free space from the hardrive itself…

UPDATE:

Forgot to mention a few things…

I’ve formatted my HTPC a few days ago, so everything is clean and fresh. I haven’t done any defragmentation and don’t normally do that anyway, but just to point out, I haven’t defragged at all before instaling CTM OR after.
I have CCleaner installed but have never used the “Free Wipe Space” option. It’s unticked by default anyway.
I have Auto Disk Defragmentation OFF.

And funny enough, I found my old thread about the same problem that i posted almost a year ago, here:
https://forums.comodo.com/help-ctm/lost-all-my-snapshots-really-weird-problem-please-read-t51435.0.html;msg367336#msg367336

this time, everything is followed and setup correctly but the problem still exists. On my better PCs, i’m happy to keep CTM on but on my HTPC currently, it’s just annoying to deal with. I hope there’s a solution to this, someday.

By the way, how are people suppose to defragment if they have CTM installed? Or will they never be able to then?

carfal · November 27, 2010, 5:53am

EDIT: Sh*t. Just read your update. Would have saved a lot of time. Funny…I replied to the post you linked as well ;D

But on my HTPC used for work purposes mostly, where i have a 100GB hardrive which is super small, CTM just doesn't seem to use more space from the hardrive than it should be. Another problem is, deleting snapshots don't free up more free spaces, which doesn't make sense as it SHOULD.

Did you run the “Compact” option manually after you deleted these snapshots? The free space is recovered only after this is performed.

I'm planning on doing an actual defragmentation of my hardrive using Smart Defrag or Defraggler, but i don't think that's necessary as CTM isn't recognizing there're at least 10GB+ of free space left to use rather than the 1486MB it shows.

I believe external defraggers are disabled in the latest version of CTM because it only results in a huge snapshot because of the way CTM protects data. It will only add to your free space woes.

Anyway, isn't there a way to make CTM increase the free space usage?? It seems to have a limited defined usage rather than take the free space from the hardrive itself....

Chaoscreator i believe your free space issues are resulting from a lack of understanding on how CTM protects its data. This not meant as an insult or attack.

I’ve attempted to explain a few times in these forums on how CTM works so i’ll give another explanation here. This concept is difficult for some people to grasp and there is no simple way to explain it but here goes.

You start with your Installation snapshot. Then

you create a 4GB file called F1. You create another 4Gb file called F2
you delete file F2 and take a snapshot called SS1
You create another 4Gb file called F3 and delete file F1
Take a snapshot called SS2
Create a 4 GB file called F4
Take a snapshot called SS3
Delete file called F4

So on a normal system without CTM installed you would expect to have used only 4GB of space at this point used by F3.(adding and subtracting 4Gb your left with 4Gb if my math is correct).

Lets look at it in the CTM world. In actual fact, you are currently occupying 16Gb of “free space” ( you’ve created a 4Gb file 4 times). But what about the 3 deletes?

Remember, CTM only recovers free space when a “Compact” is performed either manually or at boot-time. But things are never that obvious in the CTM world.

Lets say we perform a defrag (otherwise known as “Compact”) after step 7. This would only recover 4GB of space that was originally used by F2 (in step 1). But why wasnt the space used by F1 and F4 recovered?

Remember that CTM will recover the space used by deleted files only if it doesnt exist in any other snapshot ie. its unique.

So the logic goes like this

F1 was deleted in SS1 but still exists in Installation Snapshot, space not recovered

F2 was deleted in Installation Snapshot but before SS1 was taken, space recovered (doesnt exist anywhere else)

F4 was deleted in SS3 but still exists in SS2, space not recovered

So now its clear (i hope) why only 4Gb of free space was recovered instead of the expected 12Gb. This enigma traps many people into filling their HDs and complaining that there is something wrong with CTM. Most people have their system set up to take scheduled snapshots every boot or even hourly. You can see how recovering “free space” would be a real problem in these scenarios. The files their trying to delete exist in many snapshots.

One more important information is that when a new file is created and a new snapshot is taken, it doest mean that a new duplicate of that file is created in each snapshot that it exists in. That would be silly. Each snapshot simply points to the same original location of the file therefore only using the space once. The only time new space is needed is if the file is modified in some way. Then CTM will need to preserve the original file and the new modified file.

In this example I’ve used a large file of 4Gb only to demostrate how easy it is to use a lot of free space while using CTM. These same priciples apply to any file size. CTM demands descipline in file management or you will run into issues.

Lastly, some other reasons for excessive disk usage is

Windows System Restore, disable it now!

Never use disk wiping programs while CTM is installed. A wiped sector will be perceived as a change in data and CTM will protect the sector resulting in huge HD free space usage.

Hope this helps.

chaoscreater · November 27, 2010, 6:05am

Did you run the "Compact" option manually after you deleted these snapshots? The free space is recovered only after this is performed.

Yes, also did it from the console at bootup as well. It freed up some, but still way too low.

Yes i also had System Restore disabled before i installed CTM.

No i haven’t used any defrag programs yet, I only formatted my PC recently and haven’t done that before or after installing CTM.

I see what you’re saying, but that’s also the point of my question. Why can’t CTM be modified so that it preserves or takes a snapshot of the system separately or independent of any other snapshots? Why does it have to consider that there’s a common file between snapshots for it to take action of whether it’ll delete or not?? It doesn’t really make sense to me. Taking an exact snapshot of what you currently have, should be independent of the other snapshots you took.

Also, I deleted all my snapshots, compacted it and still i get a low free space. I now have around 6GB, but i remembered i had like 15GB or more when i first installed CTM. I have no snapshots at all now, so what’s the problem this time??

Anyway maybe CTM just isn’t aimed for smaller sized hardrives…unfortunately it doesn’t suit my HTPC so i’ll have to remove it. However, it works great on my gaming PC so i’ll still use it

carfal · November 27, 2010, 9:37am

Why can't CTM be modified so that it preserves or takes a snapshot of the system separately or independent of any other snapshots?

Chaoscreater, I’m going to guess that your a FD-ISR user (or used to be). FD takes exactly the approach you describe. Taking snapshots with FD creates a duplicate of your current system in the new snapshot. Problem with that approach is the new snapshot size is as big as the one your duplicating. So if your system is 40Gb then the new snapshot is 40Gb. If fact every new snapshot will be 40Gb in size. A huge waste of space. Hench why FD is limited to a maximum of 10 snapshots.

CTM technology (borrowed from Horizon i might add) works in a much more efficient manner and for all intents and purposes , each snapshot is its own seperate independent system …sought of.

What do i mean? As you’ve heard CTM works on a sector level. What this means is incremental snapshots are possible therefore saving huge amounts of space as well as still giving the ability of independant snapshots.Its true that every snapshot is built upon the previous one but thats the genius of this technology. When a snapshot is taken with CTM, only the sectors with changed data are locked in and tied with that snapshot.

Hence the size of the snapshot is the size of the change in data. Do you see the advantage and incredible beauty of this technology. The unique change in data (at the sector level) is all that needs to be preserved because the rest of the data comes from the previous snapshots that this snapshot was built on. The best part is that each snapshot still runs like a full independant system. How clever is that!

Why does it have to consider that there's a common file between snapshots for it to take action of whether it'll delete or not?? It doesn't really make sense to me. Taking an exact snapshot of what you currently have, should be independent of the other snapshots you took.

In light of what i’ve just explained, can you see why with CTM if a file exists in more than one snapshot then this space cannot be reclaimed until the file no longer exists in any snapshot?

eg. I create a file in SS1 then take SS2 and SS3. Now i delete this file after SS3 and take SS4. You would still expect to see this file in SS1, SS2 and SS3 when you rollback to them right? The only way this is possible is if CTM protects the file from ACTUAL deletion because its still expected to be there in SS1, SS2 and SS3.

The technology that CTM uses hates duplication. The technology that FD-ISR uses lives by it.

I don’t know how else to explain it so i hope it’s now clear as to how this works.

carfal · November 27, 2010, 9:52am

Also, I deleted all my snapshots, compacted it and still i get a low free space. I now have around 6GB, but i remembered i had like 15GB or more when i first installed CTM. I have no snapshots at all now, so what's the problem this time??

This does seem like an issue for what i dont have an answer for. Perhaps Comodo should look into this.