I am sorry I read this three times but it went right over my head . You are talking about spare sector spaces, what percentage is allocated for these? Seems I could have 80% of my drive empty but bad sectors cannot be moved out of the way? How do I interpret your second paragraph with respect to using an image of a drive with bad sectors? Are you saying bad sectors are left behind on the original drive?
The HDD itself, unbeknownst to the OS, manages its own sector spaces when it comes across an error. The nature of most sector errors on an HDD is intermittency. The drive incurs a minor head crash and causes the surface under the head to lose some of its magnetic properties. This in turn may start causing "soft" read errors (errors whose DATA can be corrected using included detection/correction DATA included in the sector) of that compromised surface. Using its own internal criteria (bad or good) it will then relocate that DATA to another sector on the disk and "patch out" the questionable sector so it cannot be reused... this will be done to a sector that Windows knows nothing about (a spare sector pool managed by the disk controller/firmware). As far as Windows is concerned, nothing has changed on that disk during this process. The disk is nice enough to let you know about this type of incident in its SMART dataset. From here on two things can happen. A sector can actually fail in a hard way, never to be recoverable (crash on surface was catastrophic, surface no longer usable). When this happens, the disk reports such a fact to the OS, which then reports such a fact to the application trying to read that sector... application loses. The second situation is when the disk is heavily involved in sector relocation due to massive soft errors that it starts running out of its "spare" sectors to reallocate to. When that happens, disk reports "hard" error to the OS which forwards that info to the requesting app... app loses again. Basically, if the image taken had no reported errors, the DATA within that image is fine...
I don't think there is a standard % of any given drive reserved, but it is probably a very small percentage on average.
The image is unaffected. It will be the same for either a case of no bad sector, or the case of a reallocated sector. The bad sector remains on the drive, though the data has been moved to another (spare) sector. This fact is kept secret from the operating system, because the disk drive is ashamed. Here is a crude analogy: You frequent a restaurant with valet parking. You don't know where your car is physically parked, but you always get the same car back from the valet after you dine. One day, a mishap occurs where a wrecking ball was dropped on the spot where your car was usually parked. The valet doesn't mention this accident when you dine later that day, but simply parks your car in a VERY small lot he has set aside for these sorts of rare problems. You enjoy the usual great dinner, and drive home in the same old car as usual, and you are very satisfied. So, the net result is: You _never_ knew exactly where he parked your car before, and you _still_ don't know where he parks it now. But you always got the same old car back, both before and after this wrecking ball accident. You can't tell the difference! In this analogy: You are the operating system, .eg. Windows The valet is the internal controller inside the disk drive. Hope this helps a little.
TheRollbackFrog has given an excellent explanation of how sector swapping works. I will only add that even if the spare sector allocation has been exhausted, leaving you with bad sectors that can’t be “masked”, then you could still get completely valid images of the system if the bad sectors are in space that is currently marked as free by the overarching file system. This assumes you are using the default intelligent sector copy that only looks at sectors that contain actual data according to the file system. If you use forensic mode, then Reflect would attempt to read all sectors within the partition space — though not sectors that have been masked off by the drive’s firmware, as TheRollbackFrog notes. The drive doesn’t offer a way to read those anymore, at least not any standard way. But apart from the forensic scenario, the only situation where you can have a problem would be if you have actual data stored in a bad sector where a spare isn’t available or where the drive can’t get a good read of that sector in order to copy the data to a spare sector in the first place. In those cases, if you choose to enable the option to ignore bad sectors, then Reflect will record whatever it can from such sectors. That might result in a corrupt file. And thus to Beethoven’s question, in the scenario I just described, yes you could potentially restore corrupt data onto a new system. You wouldn’t restore an actual bad sector of course, but what you would essentially have is a new drive that is able to reliably read a sector that contains corrupt data.
thank you guys for your great explanations - much clearer now. I feel I am in a slightly better position with respect to my drive given that I have good images. However given TheRollbackFrog's references to when the disk is heavily involved in sector relocation due to massive soft errors, I will retire this drive shortly.
@TheRollbackFrog, @jimminy, @jphughan, from my side too many thanks for your interesting and useful explanations.
^ You're missing the first two bullet points of that release's notes, one around localization and one around a new utility called MRAuto (not available in Reflect Free).
I had to update it manually since the auto-updater crashed on my system (several times) with the following event. Can someone report this? OS Win 10 21H2 (with all updates). Updated the Boot Menu just fine.
I am glad to see I am not the only one with the issue. Some friends reported the same. https://malwaretips.com/threads/macrium-reflect-v8-updates-and-discussions.108229/post-988301
Unfortunately, Macrium does not provide that option for Win7, nor is it available on their Free version - only Light Mode.
Had a smooth upgrade today from Macrium Reflect Home 7.3.6391 to 8.0.6758 All previous settings present and accounted for!
[Issue resolved - see edit #2 at bottom] One minor niggle with 8.0... At every Macrium launch, Windows is now warning me that I have "untrusted font blocking" enabled in group policy (I do), and that some user interface elements may not display correctly. I don't notice anything wrong with the display. Is there something I may be missing here, before I dismiss this alert permanently? Edit: I just realized that I have this set to audit, but not block untrusted fonts. So that would explain why the display appears normal. "This security feature provides a global setting to prevent programs from loading untrusted fonts. Untrusted fonts are any font installed outside of the %windir%\Fonts directory. This feature can be configured to be in 3 modes: On, Off, and Audit. By default, it is Off and no fonts are blocked. If you aren't quite ready to deploy this feature into your organization, you can run it in Audit mode to see if blocking untrusted fonts causes any usability or compatibility issues." I didn't get this message with Macrium Reflect 7.x... Edit #2: Found this on Macrium Knowledgebase > https://knowledgebase.macrium.com/display/KNOW80/Toolbar and Application Icons Hidden Macrium Reflect v8 with no icons Unlike earlier versions of Macrium Reflect, application icons are now vector fonts rather than bitmap images. This enables crisper display on all screen resolutions as the icons are drawn rather than painted pixel by pixel. Macrium Reflect is being prevented from loading its vector font by a Windows Group Policy setting. Why is this happening? A few Windows installations have a legacy, and redundant, Windows Group Policy setting called 'Untrusted Font Blocking' enabled, and this prevents all applications from loading private fonts. We believe that this, redundant Group Policy, may only be set for Windows 10 installations upgraded from Windows versions earlier than Windows 10, but whatever the reason, it should be disabled.
Moved to new hardware on one pc ( Win 10 Pro on Dell T5600 x64 Bios Legacy) and found out that both Macrium and IfW usb sticks don't let me boot up. For Macrium I had upgraded the program to the latest version and rebuild the Bootup Media, so did not expect any issues. I don't think it's the USB stick but something else not properly set up in the hardware. Having changed the Bios boot sequence to boot via Legacy / USB Storage Device first and then the main os, I am getting "selected boot device failed". Given that I had created this stick on the new pc, I would have thought that the rescue media (Windows RE 10 Version 2004 (64bit) Macrium 8.0.6758 )would allow me to boot up the pc ? The Macrium Windows Boot Menu shows up as expected.
Brian, I tried that before and I can only see for Boot Sequence _Diskette Drive _USB Storage Device _CD/DVD/DR-RW-Drive _Onboard Nic _PO:CT500MX500SSD1 and underneath Boot List Options _Legacy _UEFI I ticked USB Storage and PO was ticked before - don't know what onboard NIC is. Originally PO was at the top and I moved USB to the top assuming this would mean the USB stick would be tried first.
Onboard NIC is the network interface controller (Ethernet) for PXE booting. Are the USB sticks formatted as FAT32 or NTFS? Try the former if you haven’t already. That shouldn’t matter if you’re using Legacy BIOS booting (though I don’t recommend that anyway), but it’s typically required for UEFI booting, since only a small handful of systems/boards implement the firmware-level support for NTFS that is optional in the UEFI spec. If for some reason you need to continue with Legacy BIOS booting and your system only offers a generic “USB Storage Device” option rather than enumerating specific devices, then make sure no other USB storage devices are attached at startup. Some systems with that generic option only try one such device, and if it’s unbootable or not the one you wanted, then that’s just tough luck for you. And I agree with Brian that you should always use the one-time boot menu for scenarios like this, rather than mucking around with your default boot order.
jpughan, thank you - regarding the formatting, I never formatted the sticks in the past, just followed the procedure to create the bootup sticks and it just worked on my other pc. Regarding Bios booting, I don't have a preference but this is the way the pc came and I normally would not think of touching that. There are other external usb connected for backups, so I will try to remove them all next time I try but again, never had to do this before. Seems this Dell has some particular requirements As for the boot order, thought it might make it easier to start from a usb if I don't have to hit whatever the relevant key is during that short window of opportunity but happy to go back to default in this case. Anyway the underlying issue was there before I changed the bootorder, hopefully removing all external drives will be the answer.
I don't mess with the boot order anymore, as long as my primary OS boots normally, I'm good with that! To boot from a USB stick I just select F2 or Del at system bootup to get into the UEFI/BIOS. In there is a Function key for quick boot, where I can select the specific drive that I wish to boot from. Boom, done!