Hi guys, I’ve just installed NIS 2011 and performed a full system scan. I’ve set the trust setting to full so there is no files skipped during a full system scan, but I noticed in the scan report that over 3,000 files have been skipped! Any ideas as to why NIS is not scanning these files? I’ve looked through the logs, but nothing helpful there unfortunately. Thanks in advance, Jen
Many thanks Allen for the quick reply and information. I will give this a try and report back. Thanks, Jen
Sorry, I have another question: Is this behaviour related to the caching option? If I disable this, will the skipped files return to 0? Thanks, Jen
Hi guys, I’ve just installed NIS 2011 and performed a full system scan. I’ve set the trust setting to full so there is no files skipped during a full system scan, but I noticed in the scan report that over 3,000 files have been skipped! Any ideas as to why NIS is not scanning these files? I’ve looked through the logs, but nothing helpful there unfortunately. Thanks in advance, Jen
miss_fugg wrote:
Sorry, I have another question: Is this behaviour related to the caching option? If I disable this, will the skipped files return to 0? Thanks, Jen
Hi Jen,
No problem, please ask any questions you wish.
No this would have little or no affect. From NIS Help on Caching:
Improves the performance of your computer. If you turn on this option, Norton Internet Security keeps a record of the files that are accessed often. Norton Internet Security does not scan those recorded files, even when you restart your computer.
This is referring to files which are in memory or accessed very frequently so it is related but not the same as "skipped" files.
Skipped files are files (whether accessed often or not) which have already been scanned and known to be clean and they will be scanned again if changed or when new definitions are downloaded.
Not sure but Caching might have a minor impact on the number of skipped files but it definitely will not eliminate skipped files.
Good question by the way. 
Hope this helps to clarify.
Best wishes.
Allen
Thanks for clearing that up, Allen! 
I have a couple of questions too, if you don't mind:
1. Is there a way to completely disable this aforementioned scanning so that there are no skipped files when running a full system scan?
2. What is actually scanning these files that are skipped during the full system scan? Idle scan maybe?
Kind regards,
T
Here's a recent post about skipped files during scans. Some of us think that Norton caused the skipped file problem on 11/15 when definitions were updated. Here's the link: Skipped Files
Marty wrote:Here's a recent post about skipped files during scans. Some of us think that Norton caused the skipped file problem on 11/15 when definitions were updated. Here's the link: Skipped Files
Hi Folks,
As I have mentioned on the referenced thread it is perfectly normal for FULL System Scans to have skipped files. This is NOT anything new. It has been this way for a very long time. Skipped files are files which have already been scanned by Norton and have not changed and hence are not scanned the next time around. They get rescanned either when the file changes or when new definitions are downloaded.
Just one thread (which predates 11/15) is shown below:
If you search through the forums here you will see numerous references to this. FULL system scans have always had a tendancy and typically do have some number of skipped files.
If you check your NIS history (if it goes back prior to 11/15) and pull up FULL system scan predating 11/15 you will also see this or search the forums.
What is NEW since 11/15 is that Quick Scans now also report Skipped files. That did not occur prior to 11/15 and Floplot requested input from Symantec on that and we are still waiting for a final answer on what change triggered this.
I did not bring that up in this thread initially because this thread is asking about skipped files on FULL system scans which again is normal.
Hope this helps.
Best wishes.
Allen
Hi Allen,
Not sure if you're referring to NIS 2010 too, but on my 2010 version of the software full scans reported NO SKIPPED files.
T
thommo14 wrote:I have a couple of questions too, if you don't mind:
1. Is there a way to completely disable this aforementioned scanning so that there are no skipped files when running a full system scan?
2. What is actually scanning these files that are skipped during the full system scan? Idle scan maybe?
Kind regards,
T
Hi thommo14,
Please see my previous post regarding when skipped files get rescanned.
There are basically two types of files which may not get scanned during a particular full system scan.
Trusted Files - controlled by Scan Performance Profiles. If you set this option to FULL you should have no trusted files show up in the details - e.g., instead they will be scanned each time. This might in turn have a minor impact on skipped files but probably not much / if any.
Skipped Files - again these are files which have previously already been scanned by NIS and known to be safe. You can possibly "reduce" the number of skipped files by setting the cache option to OFF. But you will not be able to totally eliminate skipped files.
The idea behind both of these is to reduce the amount of time and workload needed to perform a full system scan. With the Scan Performance Profiles it is a personal choice if you really want to have known files scanned each and every time. The technology behind both trusted and skipped files is pretty mature at this point and my opinion is that there is no additional risk by having Scan Performance Profiles set to the default of Standard Trust. I would not however recommend High trust as that probably does pose a little additional risk.
Hope this helps.
Best wishes.
Allen
thommo14 wrote:Hi Allen,
Not sure if you're referring to NIS 2010 too, but on my 2010 version of the software full scans reported NO SKIPPED files.
T
Hi thommo14,
Not every scan will show skipped files but it is perfectly normal for it to do so. Whether a file is skipped or not depends on when it was last scanned and other factors.
if you look at the thread I referenced the question was posted against NIS 2010.
NIS 2010 and 2011 work the same in this regard.
Also be aware that the "numbers" of files reported as "scanned", "skipped" and "trusted" also has a known bug. So the exact numbers may not be 100% accurate but it is absolutely normal for a full system scan to have "skipped" files.
I referenced one such thread, I could easily locate many others.
This is a common question which comes up on the forums so if you search around you will find many, many threads on the same topic.
Best wishes.
Allen
Hi Allen,
______________________________________________________________________________________
AllenM wrote:
As I have mentioned on the referenced thread it is perfectly normal for FULL System Scans to have skipped files. This is NOT anything new. It has been this way for a very long time. Skipped files are files which have already been scanned by Norton and have not changed and hence are not scanned the next time around. They get rescanned either when the file changes or when new definitions are downloaded.
______________________________________________________________________________________
I can't comment on the behavior of OTHER computers pertaining to skipped files or categorize what is perfectly normal for THOSE computers.
However, prior to 11/15/2010, for both of MY computers, Norton Security History has not reported a single skipped file in any type of scan with the Scan Performance Profile set to Full Scan. (I have Idle Full Scan set to not run).
I'm cautious of sweeping generalizations.
Thanks Allen, was just a bit worried that certain files aren't scanned. I know this is very probably safe and normal, but for paranoid individual such as myself (
) I think it's reassuring to see 0 files skipped during a scan. Wish there was a way to disable this.
Thanks for your support though.
Kind regards,
T
Marty wrote:Hi Allen,
______________________________________________________________________________________
AllenM wrote:
As I have mentioned on the referenced thread it is perfectly normal for FULL System Scans to have skipped files. This is NOT anything new. It has been this way for a very long time. Skipped files are files which have already been scanned by Norton and have not changed and hence are not scanned the next time around. They get rescanned either when the file changes or when new definitions are downloaded.
______________________________________________________________________________________
I can't comment on the behavior of OTHER computers pertaining to skipped files or categorize what is perfectly normal for THOSE computers.
However, prior to 11/15/2010, for both of MY computers, Norton Security History has not reported a single skipped file in any type of scan with the Scan Performance Profile set to Full Scan. (I have Idle Full Scan set to not run).
I'm cautious of sweeping generalizations.
Hi Marty,
My sincere apologies if it sounded like I was making sweeping generalizations about other computers. That is not my intent.
Every system is different as you said. All I can tell you (and this has come directly from Symantec) is that the very design of the "scanning engine" as it were causes files to be "skipped' when certain criteria are met. I cannot tell you what all the criteria are but I do know that couple of key factors come into play. 1. FIles have been scanned before and no changes have taken place to the file. 2. When new definitions are downloaded the "skipped" files are scanned again or when the files themselves change. There might be other other critiera as it relates to #1 and 2 but these are the primary ones.
Since the design itself will cause this when this criteria is met, it is considered perfectly normal when a user reports that files have been skipped during a full system scan.
The following post by SendOfJive aptly describes one thing we do look at to determine if there might be a problem:
Then there is the bug which causes the exact numbers of reported files in each category to be off by some factor which makes things even more confusing. 
This bug was also confired by Symantec and pre-dated 11/15. It is also reportedly fixed in the N360 BETA and will be rolled into NIS/NAV at some point TBD.
By the way I have tested manual full system scans, Idle full scans and scheduled full scans with Scan Performance profile set to FULL, Intelligent Skip scanning OFF and Cache OFF and even with this combination, I see "skipped" files being reported.
So again, sorry if it sounded like I was making generalizations. My only intent is to let folks know that the design of the program has criteria that when met will cause "skipped" files.
Hope this clarifies where I am coming from.
Best wishes.
Allen
thommo14 wrote:Thanks Allen, was just a bit worried that certain files aren't scanned. I know this is very probably safe and normal, but for paranoid individual such as myself (
Thanks for your support though.
Kind regards,
T
Hi thommo14,
Please feel free to suggest this in the Norton Ideas Forum.
Symantec added the setting for Scan Performance Profiles because of user input and the "skipped" files is one other area where it would give the user additional control.
Best wishes.
Allen
__________________________________________________________________________________________
AllenM wrote:
My only intent is to let folks know that the design of the program has criteria that when met will cause "skipped" files.
__________________________________________________________________________________________
Hi Allen,
Some further info about the criteria ...
Regards,