Questions about RBrx9 (I'd like answers from devteam)

[pandlouk]

After testing RBrx9 and realizing what is happening and why the 2 of the 3 bugs (table corruption and bad read/write speed) posted here RollbackRX 9 1 critical and 2 minor bugs. occur; I would like to ask why you have decided to use the windows paging file for redirecting the I/O's.
How can you ensure that:
1st. the Paged Address Pools and the System Page Table Entries will have enough space for the OS, the multiple users logged-in, etc.?
2nd. What will happen during operations that are I/O demanding like video/audio editing and demanding gaming?
3rd. What will happen if the user have a small customed size page file?
4rth. What will happen if the user has the page file on another disk? The input/outputs will have to pass first from the paging file and then go to the RBrx's snapshot files. Doesn't it reduce further the overall I/O speed?
5th. Instead of using the page file of windows why not use a dedicated page file of RBrx?

I'd like to have answers from the devteam.

Thank you,
Panagiotis

[devteam]

Hello, the basis of all your questions is that Rollback use the Windows paging file for redirecting IOs, this is not true. Rollback does not tamper, alter or restrict how Windows pagefile works. Basically to Windows pagefile, Rollback is not even there.
I know this probably does not answer your questions. So let’s step back to a more basic question. Why do you think Rollback use the Windows paging file for redirecting the I/Os? Did you see something that makes you to think this way? Maybe the answers to that question can answer your questions here. Thanks.

[pandlouk]

Originally Posted by devteam

Hello, the basis of all your questions is that Rollback use the Windows paging file for redirecting IOs, this is not true. Rollback does not tamper, alter or restrict how Windows pagefile works. Basically to Windows pagefile, Rollback is not even there.
I know this probably does not answer your questions. So let’s step back to a more basic question. Why do you think Rollback use the Windows paging file for redirecting the I/Os? Did you see something that makes you to think this way? Maybe the answers to that question can answer your questions here. Thanks.

Hello,

thank you for the answer.
You are right, it seemed to me Rollback 9 used the page file for the I/O redirection, because of the very strange hook/rootkit technic, that you apply at the virtual memory.
After your explanation and playing a bit more with the page file (resizing, moving it in different partition/disks) I see that Rollback does the exact opposite. It virtualizes the page file in its hidden system.

Now I have other questions.
1. The virtualized pagefile is it one contiguous file or does it get smaller/bigger depending on the need of the real one? Maybe the inconsistance in I/O speed that I saw is caused because the virtualised pagefile gets fragmented.
2. If I install the Rollback without a page file in the protected partitions, will it still be virtualised from rollback?
3. When installing Rollback without a pagefile and after the reboot we create one, it is not displayed in the explorer (or in the defrag apps), although windows knows there is one. Would the users benifit doing such installation, since it frees a lot of space from the baseline or there could be potentional problems?

thanks,
Panagiotis

[HDS-Stormy]

Originally Posted by pandlouk

Hello,

thank you for the answer.
You are right, it seemed to me Rollback 9 used the page file for the I/O redirection, because of the very strange hook/rootkit technic, that you apply at the virtual memory.
After your explanation and playing a bit more with the page file (resizing, moving it in different partition/disks) I see that Rollback does the exact opposite. It virtualizes the page file in its hidden system.

Now I have other questions.
1. The virtualized pagefile is it one contiguous file or does it get smaller/bigger depending on the need of the real one? Maybe the inconsistance in I/O speed that I saw is caused because the virtualised pagefile gets fragmented.
2. If I install the Rollback without a page file in the protected partitions, will it still be virtualised from rollback?
3. When installing Rollback without a pagefile and after the reboot we create one, it is not displayed in the explorer (or in the defrag apps), although windows knows there is one. Would the users benifit doing such installation, since it frees a lot of space from the baseline or there could be potentional problems?

thanks,
Panagiotis

Hi there Pandlouk,

Glad that Devteam was able to assist you with your first question, I'll make sure he knows you have some follow up questions!

Maxxy

[devteam]

Hello again:
“The virtualized pagefile is it one contiguous file or does it get smaller/bigger depending on the need of the real one? Maybe the inconsistance in I/O speed that I saw is caused because the virtualised pagefile gets fragmented.“

Yes the virtual pagefile implementation is in one contiguous file which grows/shrinks as needed, it’s not a fixed size. The inconsistent I/O speed can be caused by many factors, the virtual pagefile fragmentation could be one of them. It’s like the millage of a car, even the temperature of the day can affect it to a degree.

“If I install the Rollback without a page file in the protected partitions, will it still be virtualised from rollback?”
If there is no pagefile, assuming there is no disk IO to the pagefile, so no pagefile virtualization is being done by Rollback.

“When installing Rollback without a pagefile and after the reboot we create one, it is not displayed in the explorer (or in the defrag apps), although windows knows there is one. Would the users benifit doing such installation, since it frees a lot of space from the baseline or there could be potentional problems?”

It’s not a good idea. Yes you do save some disk space in the baseline snapshot if there is no pagefile at setup. But as soon as you finish the setup, you have to create a pagefile, so the disk space is not saved. The pagefile virtualization is implemented with a pagefile present in mind. Without a pagefile, it won’t be any sever problems (because this is an optimization feature, not a essential requirement).Rollback just won’t run efficiently.

[pandlouk]

Ok, thanks

Panagiotis

[Owl]

I'm trying to get my head around this.

What I'm thinking is that the page file will show significant differences between snapshots, and therefore occupy a lot of space in snapshots if it is included in the rollback set.

Is it? Does it have to be? Would it be better placed on a non-RBRx volume?

[HDS-Jacob]

Hi again Owl. I will flag this to see if we can get you an answer.

Best,
Jacob

[Owl]

Thanks, I'm sure a lot of people will be interested in the answer and explanation.

Maybe I'm being dense here, but when I look at the Knowledge Base (referred to occasionally in forum posts) I can only see one article relevant to RollBack Rx, and that is to do with the log files. It does not seem to have the content that other posts mention. Am I getting something wrong?

[HDS-Jacob]

Not at all Owl. If I understand your question correctly, links from the knowledge base copied and posted into the forum will not include the page with the search result. However, going directly to the support site Horizon DataSys Support Portal are several topics on Horizon DataSys products. There is a category on Rollback RX Pro on the left-hand side. Just click on the plus sign and topics on Rollback will appear. You can also try doing a search for keywords in the search field right above it. I hope this answers your question? Let us know.

Best,
Jacob