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Firefox randomly access $MFT (Master File Table) of other HDDs

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Hi,

I have couple of hard drives on Windows 8.1 and while I'm using Firefox; "Windows Explorer.exe" randomly access to $MFT (Master File Table) of other internal or external harddrives, which I don't use at that moment.

I used Resource Monitor and SysInternals to see what happens but I only figured out Firefox triggers an access to $MFT of other hard drives.

As I figured out, sometimes when I open a new tab, or, sometimes after reading a long article on a website and when I open a Youtube tab, or, sometimes after some reading when I download an image; Firefox Browser triggers Windows Explorer.exe and it access to $MFT (Master File Table) of other drives. And they make noise, that's why I'm asking.

I checked if it happens with other browsers or programs; I found that this happens with Firefox or Chrome browser. But not while using Microsoft Edge browser or any other programs.

Windows Search Indexing turned off, PageFile turned off. There is not any programs on other drives. There is no background application and no antivirus. There is no Firefox related files (bookmarks etc) in other drives.

Can you please suggest me anything to find what causes/triggers that or suggest me to how to use properly SysInternals or anything else to see why Chrome and Firefox wants to reach other hard drives? (Such as how to setup a filter in Process Monitor / SysInternals or anything else... )

Thanks for any help.

Hi, I have couple of hard drives on Windows 8.1 and while I'm using Firefox; "Windows Explorer.exe" randomly access to $MFT (Master File Table) of other internal or external harddrives, which I don't use at that moment. I used Resource Monitor and SysInternals to see what happens but I only figured out Firefox triggers an access to $MFT of other hard drives. As I figured out, sometimes when I open a new tab, or, sometimes after reading a long article on a website and when I open a Youtube tab, or, sometimes after some reading when I download an image; Firefox Browser triggers Windows Explorer.exe and it access to $MFT (Master File Table) of other drives. And they make noise, that's why I'm asking. I checked if it happens with other browsers or programs; I found that this happens with Firefox or Chrome browser. But not while using Microsoft Edge browser or any other programs. Windows Search Indexing turned off, PageFile turned off. There is not any programs on other drives. There is no background application and no antivirus. There is no Firefox related files (bookmarks etc) in other drives. Can you please suggest me anything to find what causes/triggers that or suggest me to how to use properly SysInternals or anything else to see why Chrome and Firefox wants to reach other hard drives? (Such as how to setup a filter in Process Monitor / SysInternals or anything else... ) Thanks for any help.

All Replies (11)

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hello,

It slows down any other processes which are working with the HDD to a near-standstill whenever it happens, so I have recently started navigating ... Missing: Firefox ‎| Must include: FirefoxI used Resource Monitor and SysInternals to see what happens but I only figured out Firefox triggers an access to $MFT of other hard drives.


I have an internal HDD which contains a directory, which contains a series of folders, which contain a total of about about 10 million small text files. Whenever I open this directory in Windows Explorer, the hard drive goes absolutely nuts and sounds like it's having a heart attack. Resource Monitor shows that it's due to a roughly 11.5 MB/sec access to the drive's NTFS Master File Table (see below screenshot):

Indexing has been disabled for this directory, and all its subdirectories, as it is known that drive indexing and large numbers of small files are a volatile combination. Likewise, the directory only contains a couple folders (each of which house a large number of files), so none of the files in question are ever being displayed onscreen. As such, I am a bit baffled as to why this intense reading occurs. It slows down any other processes which are working with the HDD to a near-standstill whenever it happens, so I have recently started navigating the drive and its contents via Command Prompt/PowerShell, which, for whatever reason, does not seem to trigger the NTFS reading-frenzy. I'm not really a tech person, and so I don't know the details of how Windows 7 accesses drives to display files and folders, so I have a couple questions: Why is the NTFS Master File Table being accessed, even though none of the files in question ever appear on screen, and none of them are ever being opened? Is it absolutely necessary? If not, is there a way to disable it? If so, what negative consequences would result? Is there a more efficient (in terms of reducing disk wear and unnecessary file table access) way to set up a directory whose sole purpose is to house a large number of files? Additional info: The drive is healthy (no S.M.A.R.T errors, and CrystalDiskInfo says there have been no problems), and is not a boot drive.

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Microsoft sets on files that you delete on the NTFS file system only one delete bit, but doesn't clear the data on the hard drive and also doesn't clear the MFT records and index data. Very small files (few hundred bytes) are stored entirely in the MFT and can thus always be recovered. Only when clusters that the deleted file occupies are reused to store other data then it isn't possible to recover a deleted file. On FAT32 (and FAT16) file systems this was more difficult, especially when a file is fragmented because on these file systems the bits that represent the cluster chain were cleared, so you had to be lucky that you could reconstruct the cluster chain. On NTFS is such a reconstruction not needed as you would only need to scan MFT. You would have to use a wipe utility on Windows to ensure that files with sensitive data are really gone and also do such a wipe if you would sell the computer. http://www.thefreecountry.com/security/securedelete.shtml


thank you

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The replies above are Spam.

Can anyone help please?

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hello!!

Have you tried loading Firefox in safe mode to see if the problem goes away?

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plzz do that then reply me what is the outcome.......

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Hi FPrince, Firefox should disregard website requests for local files, if that is the source of this. Could you confirm this preference:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box in the page, type or paste origin and pause while the list is filtered

(3) If the security.fileuri.strict_origin_policy preference is bolded and has a value of false, double-click it to restore the default value of true

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One other thought:

Firefox keeps a file of site-specific "last download directory" and "last upload directory" locations. If you have ever saved a download on or uploaded a file from the other drives, I could see that being a factor when you go to save something. I don't know how it would come into play just loading a page, but it would be nice to rule that out.

As a test, you could hide the file that stores the accumulated path information from Firefox and see whether that makes any difference. Unfortunately, this affects some other site-specific settings such as preferred zoom levels and preferred spellcheck language, but hopefully it won't be too inconvenient and you can swap the old file back later if this made no difference.

Open your current Firefox settings (AKA Firefox profile) folder using either

  • "3-bar" menu button > "?" Help > Troubleshooting Information
  • (menu bar) Help > Troubleshooting Information
  • type or paste about:support in the address bar and press Enter

In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows File Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

  • "3-bar" menu button > Exit
  • (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename content-prefs.sqlite to something like content-prefsOLD.sqlite.

Then start Firefox back up again and browse normally. Any difference over time?

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AMAN ARYAN said

hello!! Have you tried loading Firefox in safe mode to see if the problem goes away?

Thank you Aman Aryan,

I tried your suggestion; I restarted Firefox while pressing Shift and it started in Safe Mode. But after couple of minutes; when I opened a new Youtube tab, another hard drive started to spin up immediately and Process Monitor showed this:

Process Name: System Operation: ReadFile Path: T:/$Mft Result: Success Detail: Non-cached, Paging I/O, Synchronous Paging I/O

So, basically, using Firefox in Safe Mode didn't change anything. By the way, when I start Firefox, it access to Desktop.ini in another drive:

Process Name: firefox.exe Operation: CreateFile Path: N:\Desktop.ini Result: Name Not Found Desired Access: Generic Read Disposition: Open Options: Synchronous IO Non-Alert, Non-Directory File

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jscher2000 said

Hi FPrince, Firefox should disregard website requests for local files, if that is the source of this. Could you confirm this preference: (1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk. (2) In the search box in the page, type or paste origin and pause while the list is filtered (3) If the security.fileuri.strict_origin_policy preference is bolded and has a value of false, double-click it to restore the default value of true

Thank you jscher2000;

I checked:

security.fileuri.strict_origin_policy is not bolded and it has a value of True.

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jscher2000 said

One other thought: Firefox keeps a file of site-specific "last download directory" and "last upload directory" locations. If you have ever saved a download on or uploaded a file from the other drives, I could see that being a factor when you go to save something. I don't know how it would come into play just loading a page, but it would be nice to rule that out. As a test, you could hide the file that stores the accumulated path information from Firefox and see whether that makes any difference. Unfortunately, this affects some other site-specific settings such as preferred zoom levels and preferred spellcheck language, but hopefully it won't be too inconvenient and you can swap the old file back later if this made no difference. Open your current Firefox settings (AKA Firefox profile) folder using either
  • "3-bar" menu button > "?" Help > Troubleshooting Information
  • (menu bar) Help > Troubleshooting Information
  • type or paste about:support in the address bar and press Enter
In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows File Explorer. Leaving that window open, switch back to Firefox and Exit, either:
  • "3-bar" menu button > Exit
  • (menu bar) File > Exit
Pause while Firefox finishes its cleanup, then rename content-prefs.sqlite to something like content-prefsOLD.sqlite. Then start Firefox back up again and browse normally. Any difference over time?

Thanks again,

I never downloaded anything from Firefox to another drive. It simply downloads to C:\Users\User\Downloads folder. By the way, as I mentioned in previous message to Aman Aryan, even when I open a new Youtube tab Firefox wants to access to another drive: sometimes it wants to CreateFile to N:\Desktop.ini; sometimes it just wants to ReadFile to T:\$Mft.

I changed the file "content-prefs.sqlite" to "content-prefs.sqlite-backup" now as you suggested. I'll reply you.

Thank you for your help.

I really appreciate any help.

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Firefox keeps a file of site-specific "last download directory" and "last upload directory" locations. If you have ever saved a download on or uploaded a file from the other drives, I could see that being a factor when you go to save something. I don't know how it would come into play just loading a page, but it would be nice to rule that out.

As a test, you could hide the file that stores the accumulated path information from Firefox and see whether that makes any difference. Unfortunately, this affects some other site-specific settings such as preferred zoom levels and preferred spellcheck language, but hopefully it won't be too inconvenient and you can swap the old file back later if this made no difference.

Open your current Firefox settings (AKA Firefox profile) folder using either

   "3-bar" menu button > "?" Help > Troubleshooting Information
   (menu bar) Help > Troubleshooting Information
   type or paste about:support in the address bar and press Enter 

In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows File Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

   "3-bar" menu button > Exit
   (menu bar) File > Exit 

Pause while Firefox finishes its cleanup, then rename content-prefs.sqlite to something like content-prefsOLD.sqlite.