I wish there were a way to pass on the warning to people with Windows 8 machines BEFORE they do what I did.
Just to include the "repair" here,,,
Navigate to the ROOT of the SD card (for me this was 'E:')
Type attrib -S -H -R "System Volume Information" <enter>
You will then need to delete any files in the directory...
type cd "System Volume Information" <enter>
type del *.* <enter>
You can then remove the directory
type rd "System Volume Information"
Remove the SD card and switch write lock ON if you want to put the SD back in the Win 8 computer.
Have you actually tested that procedure on a card that was being refused by the ResMed machine? I am curious as to whether the ResMed machines will ever accept a card that has been written to by any process other than itself. My tests have found that it won't accept a card that has been written to in that manner, even if the file written has been deleted.
I would be interested to hear if you found that wasn't the case if/when you tested it.
08-24-2014, 09:25 PM
(This post was last modified: 08-24-2014, 09:45 PM by jcarerra.)
Yes, I have, one ime. But it is critical that no other file on the card is changed...that the ONLY change to the card was the creation of the hidden directory.
The S9 looks for "changes" on the card. I could not get the rep at ResMed to tell me exactly WHAT is looked for, but he insisted that ANY change to the files on the card would cause it--the files or their metadata.
He said ONE reason is patient protection--if card goes to doc, and there is a mix up and you are given another patient's card by mistake, it is erased so you do not have someone else's data. In short, when the card is put into your machine, it has to exactly match what the machine has in memory.
My test was I accidentally again put the card into Windows 8.1 machine with wp off. I realized it, looked for the hidden directory using the procedure as shown (attrib,, then a dir to see the now-revealed folder), finished the directory removal, (verified that with a dir also) then put the card in the S9, and it was OK.
I did NOT put the card into the S9 with the hidden directory "System Volume Information" on it and see the machine want to erase it.
There is a registry edit hack that can be done to turn off Windows 8.1 from writing "System Volume Information" to external drives. I have also done that (thankfully because again today I put in the card and forgot to slide wp off).
DO NOT DO THIS UNLESS YOU ARE CONVERSANT WITH MODIFYING THE REGISTRY
Using REGEDIT to create DisableRemovableDriveIndexing key
Prevent System Volume Information folder creation on USB in Windows 8.1
If your edition of Windows 8.1 does not have the Group Policy Editor, do the following:
1. Press Windows Key + R combination, type put regedit in Run dialog box, and hit Enter to open the Registry Editor.
2. Navigate here:
3. In the left pane of this location, right click over "Windows" key and select New -> Key.
(This assumes you do not already have a sub-key named "Windows Search".)
Name the newly created sub-key as "Windows Search" (no quotes).
Now select the same sub-key and come to its right pane.
Right click in the blank space, select New -> DWORD (32 bit) Value.
Name the newly created DWORD as DisableRemovableDriveIndexing.
4. Rt click on he new DisableRemovableDriveIndexing, select Modify, and input the Value data as 1.
You may now exit Registry Editor and reboot, this should fix the issue.
Thanks jcarerra ,
That's all good to know in case I get a Win8 machine. The tests I ran were done on Win7 machines and that explains my different results.
Since Win7 doesn't write the System Volume Information file to the SD card, my test was to simulate how Win8 writes to the card by intentionally writing a text file to the card instead, then assigning it a hidden attribute. Then deleting that hidden text file I created. The rest of the card remained the same.
The S9 refused to accept the card and offered to delete all data and format the card. I ran the test several times with the same results.
I concluded that the S9 was programmed to detect whether ANY data had been written to the card, whether it was subsequently erased or not, and would not accept the card if that had happened. I suspect it is tracking the File Allocation Table sectors since the FAT system writes unique identifiers to those sectors. When a file is added to a FAT drive, those sector identifiers are over written. Conceivably a program could be created that checked those sectors for any changes and flag the drive if it didn't match the reference assigned when the card was last written to by the favored system.
I went so far as to use xxcopy with the proper switches to copy all the data without any change to attributes or dates from the SD card, then delete all data from it and recopy it back to the card. The machine would not accept the card. In theory it was the same data but the machine knew that the card had been manipulated somehow and flagged it as not being acceptable and needing to be formatted.
I'd say that's a pretty neat protection to prevent anyone from faking the data.
Well, now I am confused as to why mine seemed to work, although I did not put it back into the machine while the added folder was on it.
I fully understand your discourse on it, and that certainly makes sense. I guess I am going to say that further testing is necessary.
One thing I should add...the ResMed rep said repeatedly, that the card and machine contain EXACTLY the same data. I thought the card had some additional data on it the machine didn't. If that really is true, we shouldn't even worry about this--just let the machine rewrite the card.
08-25-2014, 08:39 AM
(This post was last modified: 08-25-2014, 08:40 AM by surferdude2.)
(08-25-2014, 07:48 AM)jcarerra Wrote: One thing I should add...the ResMed rep said repeatedly, that the card and machine contain EXACTLY the same data.
(08-25-2014, 07:48 AM)jcarerra Wrote: I thought the card had some additional data on it the machine didn't.
It does. It contains the detailed information that can be used to make the detailed graphs that allow viewing the treatment minute by minute.
(08-25-2014, 07:48 AM)jcarerra Wrote: If that really is true, we shouldn't even worry about this--just let the machine rewrite the card.
If we do that we will lose the detailed information since it is only
written to the card and never stored on the machine.
That appears to be a moot point, at least on my system, since you have no option other than to allow the machine to rewrite the card. Well, actually you have another less savory option, you can copy the data on the card to a flash drive and then allow the machine to rewrite the card. ResScan will detect the flash drive and you will be able to allow the software to write the results to your hard drive and view the detailed graphs. You could also copy the data from the SD card to another SD card and use both of them when/if you need to refer to the detailed graphs. That card wouldn't be accepted by the machine. but under certain circumstances could be useful to you or your doctor/DME supplier.
I think it's lame that all
of the data being generated isn't written to the machine's memory area but perhaps they have motives that we don't fully understand. Even so, they should not be saying the data on the machine and the card are exactly the same.
At least we know how to work around the problem if we so choose.
Best regards, surferdude2
08-25-2014, 11:37 AM
(This post was last modified: 08-25-2014, 11:40 AM by jcarerra.)
Are you saying NO detailed data is stored on the machine?
I thought the last 7 days were.
If what you say is true, then the rep was clueless or lied. I queried him about three different times on the "same data" question and he never wavered, never said "except for" or any such.
If something is not "exactly" the same, then it is not "the same." Something either is identical or is not. There is no in between.
No detailed graphing data is stored on the machine but the last 7 days are written to the card. If the machine refuses the card without rewriting it, you will lose all of the detailed graphing data unless you have copied it elsewhere. The machine will start writing the next 7 days data to the card as they occur. When it reaches 7 days, the oldest is dumped and replaced with the current one.
The machine does store compliance data and summary data (365 days max.) on the machine and will rewrite it to the card when you insert it. That is true even if the machine insisted on rewriting the card. All you'll lose is the detailed graphing data.
I doubt the rep intentionally lied to you but he must operate under stress if he doesn't fully understand the product. In essence, the machine data and the SD card data will never be totally identical.
"No detailed graphing data is stored on the machine "
Intentional or not, he lied to me. If the detailed data is not in the machine, then the card and machine are not identical. Period. End of story. You simply cannot believe anything you hear from representatives of companies that are supposed to know their products. The effect is the same on us (incorrect, misleading information) regardless of whether it is intentional or not.